NATIONAL BUREAU OF STANDARDS REPORT

3M5

PROPOSED DRAFT OF FEDERAL SPECIFICATION AA-R-211d

REFRIGERATORS, ELECTRIC, SELF-CONTAINED , DOMESTIC TYPE

by

C. ¥. Phillips

and

P. R. Achenbach

to

Mechanical Engineering Division

Headquarters, Quartermaster Research and Development Command

<NBS>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
U. S. DEPARTMENT OF COMMERCE

Sinclair Weeks, Secretary NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director

THE NATIONAL BUREAU OF STANDARDS

The scope of activities of the National Bureau of Standards is suggested in the following listing of

the divisions and sections engaged in technical work. In general, each section is engaged in specialized research, development, and engineering in the field indicated by its title. A brief description

of the activities, and of the resultant reports and publications, appears on the inside of the back

cover of this report.

Electricity. Resistance and Reactance Measurements. Electrical Instruments. Magnetic

Measurements. Electrochemistry.

Optics and Metrology. Photometry and Colorimetry. Optical Instruments. Photographic

Technology. Length. Engineering Metrology.

Heat and Power. Temperature Measurements. Thermodynamics. Cryogenic Physics. Engines

and Lubrication. Engine Fuels. Cryogenic Engineering.

Atomic and Radiation Physics. Spectroscopy. Radiometry. Mass Spectrometry. Solid State Physics. Electron Physics. Atomic Physics. Neutron Measurements. Infrared Spectros- copy. Nuclear Physics. Radioactivity. X-Ray. Betatron. Nucleonic Instrumentation. Radiological Equipment. Atomic Energy Commission Radiation Instruments Branch.

Chemistry. Organic Coatings. Surface Chemistry. Organic Chemistry. Analytical Chemistry.

Inorganic Chemistry. Electrodeposition. Gas Chemistry. Physical Chemistry. Thermochemistry.

Spectrochemistry. Pure Substances.

Mechanics. Sound. Mechanical Instruments. Fluid Mechanics. Engineering Mechanics. Mass

and Scale. Capacity, Density, and Fluid Meters. Combustion Control.

Organic and Fibrous Materials. Rubber. Textiles. Paper. Leather. Testing and Specifications. Polymer Structure. Organic Plastics. Dental Research.

Metallurgy. Thermal Metallurgy. Chemical Metallurgy. Mechanical Metallurgy. Corrosion.

Mineral Products. Porcelain and Pottery. Glass. Refractories. Enameled Metals. Concreting

Materials. Constitution and Microstructure.

Building Technology. Structural Engineering. Fire Protection. Heating and Air Conditioning. Floor, Roof, and Wall Coverings. Codes and Specifications.

Applied Mathematics. Numerical Analysis. Computation. Statistical Engineering.

Electronics. Engineering Electronics. Electron Tubes. Electronic Computers. Electronic

Instrumentation. Process Technology.

Radio Propagation. Upper Atmosphere Research. Ionospheric Research. Regular Propagation

Services. Frequency Utilization Research. Tropospheric Propagation Research. High Frequency

Standards. Microwave Standards.

©Office of Basic Instrumentation ©Office of Weights and Measures.
NATIONAL BUREAU OF STANDARDS REPORT

MBS PROJECT NBS REPORT

1003-20-4^32 January 10, 1955 33£5

PROPOSED DRAFT OF FEDERAL SPECIFICATION AA-R-211d

REFRIGERATORS , ELECTRIC, SELF-CONTAINED, DOMESTIC TYPE

by

C. W. Phillips

P, R. Achenbach

Heating and Air Conditioning Section

Building Technology Division

to

Mechanical Engineering Division

Headquarters, Quartermaster Research and Development Command

Natick, Massachusetts’

<NBS>

U. S. DEPARTMENT 9F COMMERCE

NATIONAL BUREAU OF STANDARDS

The publication, r

unless permission

25, D, C. Such pi

cal ly prepared If

Approved for public release by the ir ln Part' ,s P

rohlbi,ed Director of the National Institute of 5tandards - Wasbingto " Standards and Technology (NIST) on October 9, 2015.

report has been specifireport for its own use,
flit

[S

in

in

I!
PROPOSED DRAFT

REFRIGERATORS, ELECTRIC, SELF-CONTAINED,

DOMESTIC TYPE

AA-R-211d

1. SCOPE AND CLASSIFICATION

1.1 Scope - Refrigerators covered by this specification are

self-contained and electrically-operated. They are of the

domestic tjrpe designed for operation in an ambient temperature up to 110°F. This specification does not include all

types of these refrigerators which are available, but is

intended to cover only those types used in quantity by the

Federal Government.

1*2 Classification

1*2.1 Types - Refrigerators are classified in four types

for the purposes of this specification depending on whether

or not they contain a frozen food storage compartment which

provides proper conditions for frozen food storage as required in 3.5.1, and whether defrosting of the cooling unit

for the general food compartment is manually-initiated

(started by the user when desired) or automatically-initiated

(started by a mechanical controller). The terms "manuallyinitiated” and "automatically-initiated" refer only to the

manner of starting the defrost and not to the means by which

the defrost is accomplished. See 3.5«3 for defrosting requirements for the four types. All types must provide a

means that will make ice in accordance with the requirements

of this specification.

Type I Without frozen food storage compartment; with

manually-initiated defrost.

Type II Without frozen food storage compartment; with

automatically-initiated defrost.

Type III With frozen food storage compartment; with

manually-initiated defrost.

Type IV With frozen food storage compartment; with

automatically-initiated defrost.
.

•

. VO ..
- 2 -

A defrosting means is not required by this specification for the cooling surfaces in the frozen food storage

compartments of Type III and IV refrigerators when these

cooling surfaces are isolated from the general food compartment. Some models of Type III and IV refrigerators

have a common cooling surface for the general food compartment and frozen food storage compartment. Because these

models must be capable of defrosting the common cooling

surface in accordance with the requirements of 3 • 5 • 3 , a

separate defrosting of the frozen food storage compartment

is not needed. Unless otherwise specified in the invitation

to bid, contract, or order, Type II refrigerators may be

supplied in lieu of Type I, and Type IV refrigerators may

be supplied in lieu of Type III.

1.2.2 Sizes - Refrigerator sizes shall be in accordance with

Table I, as specified in the invitation to bid, contract, or

order.

2. APPLICABLE SPECIFICATIONS AND OTHER PUBLICATIONS

2.1 Federal Specifications - The following Federal Specifications, of the issues in effect on date of invitation for

bids, form a part of this specification:

CC-M-636 - Motors; Fractional Horsepower, (AlternatingCurrent) . QQ-A-359 - Aluminum-Alloy ( AL-3 ) (Aluminum-Manganese )

Plate and Sheet.

QQ-S-766 - Steel, Corrosion-Resisting, Plates, Sheets,

Strips, a,nd Structural Shapes.

QQ-M-151 - Metals; General Specification for Inspection

of,

LP-406 - Plastics, Organic: General Specifications,

Test Methods.

RR-P-0021 - Packaging and Packing of Porcelain Enamel

Products and Major Household Appliances.

(Copies of Federal Specifications and the Index of Federal Specifications and Standards may be obtained upon application accompanied by check, money order, cash or Government

Printing Office coupons, to the General Services Administration, Business Service Center, Region 3, Seventh and D

Streets, S.W., Washington 25, D.C. This office will also

honor deposit account numbers issued by the Government Printing Office. Prices may be obtained from the Index of Federal

Specifications and Standards or from the GSA Regional Offices.
-

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- 3 -

Single copies of this specification and other product

specifications required for bidding purposes are available without charge at the GSA Regional Offices in

Boston, New York, Atlanta, Chicago, Kansas City, Mo.,

Dallas, Denver, San Francisco, Los Angeles, Seattle,

and Washington, D.C.).

2.2 Other publications - The following publications,

of the issues in effect on date of invitation for bids,

form a part of this specification:

Governmental

:

National Bureau of Standards Commercial Standard

CS131-46 - Industrial Mineral Wool Products, All

Types - Testing and Reporting.

Nongovernmental

Underwriters’ Laboratories, Inc. - Standard for Unit

Refrigerating Systems.

American Standards Association Standard B3$.l - American Standard Method of Computing Food-Storage Volume

and Shelf Area of Automatic Household Refrigerators.

American Standards Association Standard B3S.2 - American Standard Test Procedures for Household Electric

Refrigerators

.

ASTM Standard D$$3 - Definition of Terms Relating to

Plastics (Tentative).

ASTM Specification B124$ - Polyethylene Molding and

Extrusion Materials (Tentative).

ASTM Specification D744 - Nonrigid Vinyl Chloride

Plastics (Tentative).

ASTM Specification D395 - Methods of Test of Compression set of Vulcanized Rubber.

(Copies of ASTM specifications may be obtained from

the American Society for Testing Materials, 1916 Race

Street, Philadelphia 3, Pa.)

(Copies of National Electrical Code may be obtained

from the National Board of Fire Underwriters, $5 John

Street, New York 7, N.Y.

;

222 West Adams Street, Chicago,

111.; Merchants Exchange Building, San Francisco 4, Calif.)
.

1
- 4

-

(Copies of Underwriters ’ Laboratories, Inc., standards may be obtained from the Underwriters’ Laboratories,

Inc., 161 Sixth Avenue, New York 13, N.Y. ; 207 East Ohio

Street, Chicago 11, 111.; or 500 Sansome Street, San

Francisco 11, Calif.)

3 * REQUIREMENTS

3.1 Overall Dimensions' - Maximum refrigerator dimensions

shall be in accordance with the requirements of Table I,

The depth of the refrigerator measured from the center of

the door hinge pin to the back of the most remote component

on the rear of the assembled refrigerator shall not exceed

25-1/2 inches. The depth measured from the back of the

most remote component on the rear of the refrigerator to

the front edge of the foremost component of the refrigerator shall not exceed 33-1/2 inches. The maximum width

and height shall be exclusive of removable brackets or

hardware, except that the maximum height shall include

legs, where provided. It shall be possible to move the

refrigerator through a clear opening 30 inches wide without removing more than the door and/or hardware.

3.2 Storage Capacity - The total storage volume shall be

equal to or greater than the values shown in Table I« The

total storage volume shall be defined as the sum of the

general storage volume, the frozen food storage volume,

and the ice freezing volume as described in the American

Standards Association Standard B3&.1.

For Type I and II refrigerators the volume of the general food compartment shall be at least $5 percent of the

total storage capacity of the refrigerator as shown in

Table I.

For Type III and IV refrigerators the volume of the

general food compartment and the volume of the frozen food

storage compartment shall be equal to or greater than the

values shown in Table I.

The weight of water held by all of the ice cube trays,

with grids in place, shall equal or exceed the ice capacity

shown in Table I*

REFRIGERATOR

DIMENSIONS

AND

CAPACITIES S Q

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Frozen

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- 5 -

3.3 Net Shelf Area - 'The net shelf area shall be equal to

or greater than the shelf area shown in Table I* The

net shelf area shall be defined as the sum of the area

of the main shelves, door shelves, bottoms of suspended

containers, the liner, the shelf areas in the frozen

food storage section, in conformance with American Standards Association Standard B3$.l.

3.4 Material and workmanship - All materials forming a

part of the finished product shall be new, suitable for

the purpose for which they are used and shall be free

from all defects that may affect the serviceability and

appearance of the finished product. Workmanship shall

be first class.

3.4.1 Structural Soundness - The assembled refrigerator

shall not be visibly damaged as a result of the drop test

specified in 4.3.9. Inspection for visible damage may

include all components and shall include interior and exterior liners; all plastic parts; all interior shelves,

trays, baffles, and special storage vessels including

their supports; condensing unit; cooling unit; frozen food

compartment; and the refrigerator door. Visible damage

shall include, for example, crazing, cracking, or permanent distortion of plastic and enamelled parts; cracking

or permanent distortion of metal parts; dislocation of

condensing unit, cooling unit, frozen food compartment,

interior liner, or the refrigerator door.

3.4.2 Protection against damage by corrosion and electrolytic action.

3. 4. 2.1 Corrosion-resistance requirement - Unless otherwise restricted in this specification, wherever a corrosion-resisting metal or a metal treated to resist corrosion is required in this specification, it shall be not

mope than mildly attached after four hours’ exposure in

a salt-spray test conducted in accordance with Federal

Specification QQ-M-151.

Corrosion-resisting steel, unless otherwise restricted

in this specification, shall be tainless steel containing

not less than 1$ percent chromium and 8 percent nickel and

meeting the requirements for class 1 material in Federal

Specification QQ-S-766.
'

.
Only aluminum alloys conforming to Federal Specification QQ-A-359 shall be used for parts fabricated from

aluminum-alloy sheets or extrusions,

3. 4,2, 2 Materials requiring corrosion-resistance - Unless

otherwise required in this specification, all metals shall

be corrosion resisting or shall be treated in a manner to

render them resistant to corrosion,

3. 4* 2. 3 Retreatment after fabrication - Corrosion-resisting

material shall be normalized, and material treated for

corrosion resistance shall be retreated to restore or replace the corrosion-resisting properties, before being

assembled in any unit when fabrication tends to reduce or

remove those properties.

3. 4*2. 4 Protection against electrolytic or galvanic corrosion - Refrigerators furnished under this specification

shall be constructed with careful attention to protection

against electrolytic or galvanic corrosion. Joints between

dissimilar metals which may become wetted in service shall

be protected against electrolytic or galvanic corrosion by

proper selections of materials, plating, isolation, insulation, paint, area relationship, gaskets or other means.

Any bolts, nuts, pins, screws and such other fastenings and

fittings of metal shall be of the same material as the materials being joined or supported or shall be cathodic to

the materials being joined or supported.

3.4«3 Refrigeration system - All materials used in construction of the refrigeration system shall be suitable

for the refrigerant employed, and no material shall be used

that will deteriorate due to chemical action of the refrigerant or the oil or the combination of both.

3.4.4 Chromium plating - Chromium plating as specified herein shall consist of chromium finish over a coating of nickel

that has been applied directly to the base metal or over a

coating of copper in accordance with the following requirements.

3. 4.4.1 Plated surfaces - Plated surfaces of brass, aluminum,

and zinc alloy shall be smooth, and the plating shall be

done in a manner that will produce a durable, uniform finish. Plated finishes shall be bright or polished when visible

- 7 -

on the exterior of the refri g«?ra.fcor

3.4.4. 2 Chromium, nickel, and copper coatings - Chromium

finish shall be applied over a coating of nickel. The

nickel coating shall be applied either direct or over a

coating of copper as provided in table II below. Each

coating shall completely cover all surfaces that are

visible after installation, and shall conform to the

thicknesses shown in table II for regular grade R.

Table II. -- Thickness of chromium, nickel, and

copper coatings

Minimum thickness or

significant surfaces

Base metal and

finish

Regular - Grade R

Emergency - Grade E

Chromium plating on

brass

Copper (optional,

Tinl" rpniii rpH. _ Inch Inch

Nickel--

Chromium-'

Chromium plating on

aluminum or zinc alloy

die castings:

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-- 0.00010 - .00001

a )nnmo

0.00005

.00001

( 2 ) uUpUCI -------

Nickel (final nickel

coating)

Nickel plus copper,

total

Chromium--—

- .00030 - .00075

-- .00001

.00015

.00060

.00001

(1)

Where the thickness of nickel equals or exceeds

the thickness required for nickel plus copper, the

copper coating may be omitted,

(2)

The copper coating shall conform to the thickness given for nickel plus copper.

3 . 4.5 Plastics - All plastics used in the refrigerator

shall be fungus-resistant, and odor-free, and shall not

impart odor or taste to food or water. Plastics shall

not craze, crack, or permanently distort, from temperature

or load under conditions of normal use or during storage

in temperatures ranging from 0°F to 150°F.
' - - '

.

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3.4.

5.1

Styrene plastics

3.4.

5.1.1

Definition - As defined tentatively in ASTM

Designation D$33 styrene plastics are those plastics

based on resins made by the polymerization of styrene or

copolymerization of styrene with other unsaturated compounds®

3.4. 5.1.2 Impact resistance and quality - Styrene plastics

used in a refrigerator shall conform to the definition in

3.4. 5.1.1 and shall be virgin material except for recleaned

sprues and runners from the same molding operation. Where

styrene plastic is specified in this specification as an

optional material for door liners; breaker strips; interior trays, baffles, special storage vessels; or supports

for shelves, trays, baffles, or special storage vessels

it shall have an Izod impact resistance of at least 1 ft-lb

when tested in accordance with method 1071 in Federal Specification LP 406* Where styrene plastic is used for other

components of a refrigerator it shall have an Izod impact

resistance of at least 0.25 ft-lb when tested in accordance

with the same test method®

3.4. 5.2 Polyethylene plastics - Where polyethylene plastic

is specified as an optional material in this specification

it shall be virgin material except for recleaned sprues

and runners from the same molding process, complying with

the characteristics of Type I, Grades 2 and 3 in ASTM

Specification D124$.

3.405.3 Vinyl chloride plastics and synthetic rubbers - Where vinyl chloride plastic or synthetic rubber is specified as an optional material in this specification it shall

be virgin material except for recleaned sprues and runners

from the same molding process; it shall have a low compression set; and the plasticizer used shall not migrate

to enamels or other surfaces with which it is in contact

on the refrigerator.

Vinyl chloride plastic shall have a minimum tensile

strength of 1100 psi with a minimum elongation at rupture

of 250/& when tested in accordance with Method 1011 of

Federal Specification LP 406; and the weight loss shall

not exceed 2-1/2% when heated in accordance with test 6K

of ASTM D 744 (in the case of gaskets, the specimen may

be a piece of gasket 5 inches long)®

- 9

-

3. 4,5. 4 Thermosetting plastics - When thermosetting

plastic is specified as an optional material in this

specification it shall be phenolic or melamine plastic;

molded parts shall have a flexural strength of not less

than 7,500 psi and laminated parts shall have a flexural strength of not less than 10,000 psi when tested

in accordance with method 1031 of Federal Specification

LP 406; molded parts shall have a maximum water absorption

of 0 9 &%> and laminated parts shall have a maximum water

absorption of 4% when tested in accordance with method

7031 of Federal Specification LP 406.

3. 5 "Operating Requirements

3*5*1 No-Load Operation

3. 5.1.1 Fixed thermostat setting - The refrigerating unit

in all types of refrigerators shall be capable of automatically producing and maintaining an average temperature

of 39°F in the general food compartment in an ambient temperature of 90°F for some one setting of the refrigeration

control when tested under conditions of 4.3.2 and 4. 3.2.1*

Without any change in control settings the average general

food compartment temperature as defined in 4. 3. 1*7 shall

be 33°F and 43 C F for the tests in ambient temperatures of

70 °F and 110°F ( 4 . 3.2*2 and 4. 3*2*3). In type III and IV

refrigerators the average temperature in the frozen food

storage compartment shall be maintained simultaneously at

a control point of 12°F or lower during the three no-load

operating tests described in 4*3*2*1 to 4. 3.2. 3* The

difference in temperature between any two thermocouples

or thermometers in the general food compartment (not including vegetable drawers or other special purpose vessels)

shall not exceed 10°F« The temperature change as determined in 4.3® 5.1 caused by the C 3rcling of the refrigeration

control shall not exceed o°F in the general food compartment and 4°F in the frozen food storage compartment during

any of the no-load operating tests of 4.3*2. The condensing unit shall not operate more than 90% of the time and

shall not cycle on the motor overload protective device

during the no-load operating test in an ambient temperature of 110°F (4. 3. 2. 3).

3. 5.1.2 Adjustable Temperature Control - The average

temperature of the general food compartment shall be adjustable to any desired value in the range from 37°F to

43°F when tested in accordance with 4.3. 5.2, The change
.

.
- 10 -

in average temperature shall be accomplished by adiustment of the refrigeration control specified in

3. 9.3.3.

3.5.2 Ice-Making - The refrigerator shall be capable

of simultaneously freezing a weight of water e^ual to

or greater than the ice storage capacity shown in

Table I in 6 hours in an ambient temperature of 90°F

when tested under conditions described In 4.3.3. Refrigerators with automatic Ice-makers shall be capable

of producing and storing without attention in 24 hours

a weight of ice equal to or greater than twice the ice

capacity shown in Table I in an ambient temperature of

90°F.

3.5.3 Defrosting

3. 5.3*1 Frozen Food Storage Compartment - A defrosting

means is not required for the cooling unit of the frozen food compartment of Type III and IV refrigerators

except for the following design. If the moisture from

the air in the general food compartment accumulates as

frost on the cooling coil of the frozen food compartment such a cooling coil shall be subject to the defrosting requirements set forth in this specification

for the general food compartment.

3. 5.3.2 Automatically-Initiated Defrosting Systems - Automatically-initiated defrosting systems in all types

of refrigerators shall be of such design as to defrost

at least once during the defrost test(s) specified in

4. 3.4.3 and shall automatically restore the general

food compartment temperature to 43 °F or lower during

the 4-hour recovery period. The refrigerating unit

shall not be automatically restored to cooling operation

until the cooling unit is completely defrosted and the

refrigerator shall be automatically restored to normal

operation at any desired preselected temperature following the defrost cycle.

On Type IV refrigerators the defrosting operation

shall not raise the average temperature of the frozen

food more than 5°F.
..
11

On all t'i^pes of refrigerators with automaticallyinitiated defrosting systems the average temperature of

the genpral food compartment shall not be raised more

than 10°F by the defrosting operation when tested in

accordance with 4.3.4.

3. 5.3.3 Manually-Initiated Defrosting Systems - Manuallyinitiated defrosting systems on Type I refrigerators shall

be equipped with a control which can be manually set for

defrost. When tested in accordance with 4. 3.4.1 the cooling unit shall defrost completely and then the control

shall automatically restore the refrigerator to at least

limited operation®

Type III refrigerators shall be automatically restored to normal operation at any desired preselected

temperature following the defrost cycle. When tested in

accordance with 4»3.4»2, the refrigerating unit shall not

be restored to cooling operation until the cooling unit is

completely defrosted and the general food compartment temperature shall automatically be restored to 43 °F or lower

during the 4-hour recovery period s Manually-initiated defrosting of Type III refrigerators shall not raise the average temperature of the frozen food more than 5°F nor the average temperature of the

general food compartment more than 10°F based on one defrost per 24 hours when tested in accordance with 4. 3. 4. 2,

3.5*4 Exterior Condensation - The refrigerator shall operate without causing exterior condensation visible to the

eye or detectable by wiping with the fingers when tested

in accordance with 4.3.6®

3.5.5 Motor-overload Protective Device - The compressormotor-overload protective device shall be of the automaticreset style. It shall open the electric circuit to the

motor before the running winding of the motor reaches a

temperature of 302 °F. in case of failure of the starting

mechanism or in case of excessive overload caused by interruption of the supply of cooling air for the condenser

when the refrigerator is operated in accordance with the

conditions described in 4*3.7. Windings of fan motors, if

used shall not exceed a temperature of 302°F. under condition of locked rotor in accordance 'with test procedures

of 4. 3. 7. 3.
.
3.6 Construction - Refrigerators shall be self-contained

and completely factory assembled*

Refrigerant systems shall be dried, evacuated, and

charged with operating requirements of refrigerant and

oil* The refrigerant system, after being charged with

refrigerant and oil, shall not contain moisture in excess of 25 p.p.m. as determined by testing a sample of

the refrigerant in accordance with the requirements of

4® 3. 3* Each unit shall be provided with insulated compartment (s), evaporator( s) , condensing unit, control

devices necessary for automatic operation and protection,

and other equipment as required in this specification or

specified in the invitation to bid, contract or order,

( See 6.1).

Refrigerators shall be so designed that they will

not tip forward when the door(s) is/are opened 90 degrees

with the door shelves (if furnished) loaded as for the

drop test in 4.3*9 and the remainder of the refrigerator

empty®

3.7 Modification and Obsolescence - Refrigerators and

components thereof furnished under this specification

must be new and unused. Refrigerators operated only

_for tests to determine that they are in satisfactory

operating condition or that they will comply with this

specification will be considered new. The refrigerators

must be the product of a manufacturer who has produced

electric refrigerators for at least one year next prior

to the date of the invitation to bid, contract, or order.

Stock or commercial models modified to meet the requirements of this specification, under the waiver provision

(4.4) shall be considered the manufacturer’s stock refrigerators, unless the motor-compressor unit, the

evaporator ( s ) , the controls, the control system or the

cabinet have been modified. Modification of a refrigerator that has been approved for a contract or order

shall not be made without prior approval of the modification by the contracting officer®

3.$ Cabinet

3.3*1 Framing - Framing, if used, shall be fabricated of

steel, electrically welded, or aluminum alloy, electricaliyor gas-welded in an inert atmosphere. Steel or aluminumalloy used for framing shall be suitably treated to meet
,
the requirements of 3 .4.2,1 with respect to corrosion

resistance

3.^.2 Wood “ No wood shall be used for framing in the

cabinet construction. Any wood or wood products used

for purposes other than framing shall be treated to provide resistance to fungus, rot, and vermin.

3.0.

3 Insulation -- The refrigerator shall be insulated in

such a manner that condensation does not occur on any

external surface when tested in accordance with 4.3 .o. The insulation shall be of a type that is resistant to

fungus, rot and vermin, and shall be so installed as to

prevent settling in service. The exterior surfaces of the

insulation space shall be vapor- sealed and all insulation

spaces shall be filled completely so as to leave no voids.

3.0.

4 Exterior Casing, Interior Liner, and Finish

3.

0.

4.1 Materials - The outer casing and the interior liner

of the general food compartment, except the door liner,

shall be made of steel, corrosion-resistant aluminum alloy,

stainless steel, or corrosion-resistant aluminum alloy and

stainless steel In combination. Unless otherwise specified

in the invitation-to-bid, contract or order, steel shall

be used. Steel or stainless steel sheet used for exterior

casings and interior linings of the general food compartment shall have a minimum thickness of 0,023 i/ich whereas

aluminum alloy sheets for the same purpose shall have a

minimum thickness of 0.030 inch.

3.

0.

4. 2 Exterior Casing and Finish - The exterior casing

of the refrigerator, if of steel, shall be finished in

porcelain (vitreous) enamel or baked-on synthetic enamel,

or shall be polished stainless steel or aluminum-alloy.

Exterior casings finished in porcelain or baked-on synthetic enamel shall be white unless pastel-color ( s ) is/are

specified in the invitation to bid, contract, or order.

All refrigerators of the same type and size furnished on

a given contract shall be of the same color unless otherwise specified in the invitation to bid, contract, or order.
...

•]

'

.
- 14

3. $.4° 2*1 Vitreous Finish - Vitreous enamel on metal and

vitreous glaze on bisque shall have all coats fused on

at a temperature which will give a satisfactory color and

which will produce a hard, glossy surface* Vitreous enamel

or glaze shall be free from all discolorations, imperfections, chipped spots, fish scale, burn off, crazing, blisters which will mar the appearance of the item or leave the

base metal exposed, beads of enamel or glaze, lumps and

scumming. Bisque shall be given not less than one coat, on

each side. When vitreous enamel is applied to sheet enameling steel, the visible exposed finish shall consist of at

least one ground coat and one finish coat, and the ground

coat shall completely cover both sides of the metal. The

finished porcelain enamel shall not exceed 0*01$ inch in

thickness when measured as specified in 4*3 .10*1. The

reflectance of white porcelain enamel shall be not less

than 75 percent when measured as specified in 4. 3 <>10.2*

3.$.4o2.2 Organic Finish - Organic finish on the exterior

surfaces of the cabinet shall consist of baked-on synthetic

enamel applied to phosphatized zinc-coated steel or to

phosphatized steel and shall have a minimum thickness of

0.002 inch. The interior surfaces of the casing shall be

rust-proofed* There shall be no visible corrosion of either

the interior or exterior surfaces after four hours exposure

to a salt-spray test conducted in accordance with Federal

Specification QQ-M-151. The finish shall be durable, smooth,

continuous, nonabsorbent and free from all discoloration

or imperfections*

3 , $ . 4 .

Interior Liner and Finish - The interior liner of

the general food compartment shall be of steel finished in

porcelain enamel or shall be of polished stainless steel or

aluminum alloy, as specified, and shall be provided with

rounded corners which ma3

?’ be easily cleaned. Where porcelain enamel finish is specified, it shall meet the requirements of 3®$®4®2.1 for vitreous finish. In addition,

porcelain enamel, used for the interior liner shall pass

the test for acid resistance specified in 4.3«10.3* Unless

otherwise specified in the invitation to bid, contract, or

order white or pastel -colored interior liners for the general food compartment shall be considered equally acceptable

and all refrigerators of the same type and size furnished

on a given contract shall be of the same color.

- 15 -

3.$.4®4 Interior Liner of Door - The interior liner of the

door shall be (a) steel finished in porcelain enamel as

specified in 3. 3. 4.3, (b) stainless steel, (c) corrosionresistant aluminum alloy, (d) styrene plastic conforming

to the requirements of 3- 4. 5 and 3.4. 5«1 or (e) for Type I

refrigerators only, laminated melamine or phenolic thermosetting plastic conforming to the requirements of 3*4.5, and

3.4. 5.4. Laminated phenolic used for (a) shall have a

melamine finish on the side exposed to the interior of the

refrigerator. Steel or stainless steel sheet used for

door liners shall have a minimum thickness of 0.025 inch.

Aluminum alloy sheet used for door liners shall have a

minimum thickness of 0.030 inch. Molded styrene liners

and laminated thermosetting liners shall have a minimum

thickness of 0.060 inch. Styrene sheet material used in

forming door liners shall have a minimum thickness before

forming of 0.060 inch and the thickness shall not be reduced to less than .045 inch during the forming operation.

Styrene and laminated thermosetting plastic door liners

shall be supported in a way that prevents fracture, crazing,

or permanent distortion as a result of thermal expansion

when tested in accordance with 4.3.11. Unless otherwise

specified in the invitation to bid, contract or order, white

or pastel-colored door liners shall be considered equally

acceptable under this specification.

3.^.4. 5 Interior Liner of Frozen Food Compartment - The

interior liner of the frozen food compartment shall be made

of steel finished in porcelain enamel, stainless steel,

corrosion-resistant aluminum alloy, corrosion-resistant

copper alloy, or galvanized steel coated with not less than

1 ounce of zinc per square foot of steel surface, and shall

be provided with rounded corners which can be easily cleaned.

Porcelain enamel finish, if used, shall comply with the requirements for the interior liner of the general food compartment specified in 3.$®4®3®

3.c3. 5 Breaker Strips - Breaker strips shall be provided

for exterior door openings. Breaker strips shall be made

of a thermoplastic, a thermosetting plastic, natural or

synthetic rubber. These materials shall comply with the

requirements for plastics in 3 .4.5. If a breaker strip is

provided for the door opening of the frozen food compartment

it shall be made of a thermoplastic, a thermosetting plastic,

or natural or synthetic rubber, complying with the requirements for plastics in 3. 4® 5®
.

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.
16 -

3.3*6 Exterior Doors - Exterior doors shall be of the

overlapping type with square or beveled jambs. Outside

edges shall be rounded. Each door shall be provided

with an effective thermal barrier between exterior and

interior surfaces.

Each door shall be equipped with a means for holding it in a closed position with sufficient force to

effect the gasket seal required below, and conveniently

located handle for opening the door shall be provided

suitable for easy operation with one hand. The device

for holding the door closed shall be adjustable to compensate for reduction in original gasket thickness of at

least 20$ or shall be designed to automatically provide

sufficient holding force to effect the gasket seal required

over a range of gasket thickness at least from 100 to $0$

of original gasket height or thickness. Original gasket

thickness shall be measured at the free side of the door

with the door closure as adjusted by the manufacturer or,

if necessary, adjusted to effect the gasket seal required

below. Each door shall be equipped with substantial semiconcealed hinges of corrosion-resistant material or material

treated to render it corrosion-resistant and which are adjustable as required to compensate on the hinge side of

the door for at least 10$ reduction in original gasket thickness.

Each door shall be equipped with a replaceable cushiontype formed gasket made of natural or synthetic rubber or

vinyl chloride plastic. The material used shall comply with

the requirements for plastics in 3.4.5 and 3.4. 5.3 and shall

have a compression set of less than 20$ when tested in the

following manner: A one-inch section of the gasket shall be

compressed in the direction of normal use to 60$ of the

original free height in a device described in Method B of

ASTM D395 and held for 7 days at 70°F. The free height

measured 30 minutes after removal from the test block shall

be 30$ or more of the original free height. Gaskets shall be

fitted so that a single strip of paper of the width and thickness of the new United States paper currency cannot be withdrawn freely without resistance at any gasket contact when

the door with gasket is normally closed.

Doors shall swing to the right or left as specified in

the invitation to- bid, contract or order. A right-hand swing

shall be described as having hinges located on the right side

of door when facing the refrigerator.
'

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3.3.7 Shelving -

r^he general food compartment shall be

equipped with shelves of the wire-or-bar-type except that

the shelf over the vegetable drawers or crispers ma3/ be of

glass. Wire-or-bar-type shelves shall be made of passivated stainless steel; anodized aluminum alloy steel

plated with copper, nickel, and chromium; or steel, electroplated or hot-dipped in zinc and covered with baked lacquer.

Anodized aluminum alloy and zinc-coated steel used

for shelving shall not exhibit more than 3 visible spots

of attack in 12 sq. in. of shelf area after 24 hours exposure in a salt-spray test conducted in accordance with

Federal Specification QQ-M-151*

For sliding shelves the cabinet shall be equipped

with stops that prevent unintentional complete withdrawal of the shelf from the refrigerator and contact

damage to the liner 'when the shelf is pushed into the cabinet . 3.3.3 Supports for Interior Shelves, Trays, Baffles and

Special Storage Vessels - Supports for shelves, trays,

baffles, and special storage vessels shall be made of brass

plated with tin, nickel or chrominum; stainless steel; corrosion-resistant aluminum alloy; or plastic. The weight,

strength and manner of attachment of of all supports shall

be such that they will not crack, craze, become permanently

distorted, or become loosened when subjected to the drop

test specified in 4.3*9®

3.3.9 Ice-Cube Trays and Grids - Each refrigerator shall be

provided with a set of ice-cube trays and grids having a

minimum ice capacity as specified in Table I. Ice-cube

trays shall be made of corrosion-resistant aluminum alloy

or stainless steel. Ice-cube grids shall be made of corrosion-resistant aluminum alloy, stainless steel, or polyethylene plastic having the characteristics specified in

3.4*5 and 3 *4. 5*2. Ice-cube trays and grids shall be of

such design that the cubes may be readily removed from the

tray without the use of external heat.

3*3.10 Interior Trays, Baffles and Special Storage Vessels - Each refrigerator shall be equipped with a drip tray suitable

for collecting and holding the defrost water or for conveying

it to a drainage system within the refrigerator. The driptray and any other interior trays, baffles, or special storage
.
vessels furnished with the refrigerator, shall be constructed of glass, stainless steel, steel finished in

porcelain enamel, corrosion-resistant aluminum alloy,

styrene plastic, or polyethylene plastic and shall be

readily removable for cleaning . hen stainless steel finish is specified for exterior and interior liners, all

trays, baffles and special purpose vessels shall be of

stainless steel. Plastic drip trays shall conform to

the requirements of 3.4.5 and to either 3.4. 5.1 or 3.4. 5.2

whichever is applicable. Other interior trays, baffles, or

special storage vessels of plastic shall conform to the requirement

of 3.4.5. None of the trays, baffles, and special storage

vessels shall be crazed, cracked, or permanently distorted

as the result of the drop test performed on the complete

refrigerator as specified in 4*3.9*

3.3.11 Defrost Water - Defrost water shall be collected in

a readily cleanable, readily removable vessel, or shall be

carried out of the cabinet to evaporating apparatus. Adequate baffling shall be provided, to prevent defrost water

from dropping on stored food in the refrigerator. The

volume of the vessel used to collect defrost water shall

not be included in computing the total food storage volume

in refrigerators with automatically- initiated defrosting

systems. Tubes, pipes, baffles, etc., used to collect or

carry defrost water shall have corrosion-resistant surfaces,

shall be readily removable for cleaning and a trap shall be

provided in the line, if used, in which defrost water is

carried out of the refrigerator cabinet.

3.3,12 Lighting - Each refrigerator shall be provided with

interior illumination for the general food compartment.

A switch for lights shall be operated automatically by opening of door except that when multiple doors are supplied, a

single-pole tumbler-type switch with integral red pilot

light may be provided cabinet

in lieu of automatic

either door.

;he froni outside of the

switch(s) responsive to +• v.

opening of

3.9 Refrigerating System

3.9.1 Cooling Unit - The cooling unit for sizes

sive shall be designed for gravity circulation

refrigerator whereas sizes 12 and larger may be

either gravity or forced-circulation of air in

food c ompartment

7 to 11 inclu

of air in the

designed for

the general
'

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.
3 *9*1*1 Forced-Circulation Type - The forced-circulation

type cooling unit shall consist of cooling coil, fan with

motor, and housing,

3. 9.1. 1.1 Cooling Coil - The cooling coil shall be finned

tube construction using aluminum tubes with aluminum fins

or copper tubes with either copper or aluminum fins* Fins

shall be spaced not more than 9 fins per inch. The copper

coil shall be tin-plated. Where copper coil with copper

fins is used the entire coil assembly shall be hot-tindipped after fabrication. Where aluminum fins are used,

fins shall be mechanically bonded to the coil tubing. Fittings and joints shall be brazed or silver soldered*

3.9*1 .1*2 Fan - The fan and hub shall be made of brass

(electro-tin-plated), aluminum alloy, stainless steel, galvanized steel, hard rubber, or plastic. Fan and motor shall

be direct-connected,

3,9*1. 1*3 Housing - The coil housing, grilled openings, and

fan shroud, if used, shall be constructed of corrosing-resi sting steel, aluminum alloy, porcelain-enameled steel,

steel treated for corrosion resistance, or plastic,

3. 9* 1*2 Gravit 3

r Cooling Unit - Gravity-type cooling units

for the general food compartment and frozen food storage

compartment shall be made of corrosion resisting steel;

brass or copper plated with tin, nickel, or chromium; aluminum alloy; or galvanized steel, coated with not less than

1 ounce of zinc per square foot of steel surface.

3.9.2 Refrigerant Circuit - Unless otherwise specified in

the invitation to bid, contract or order, the refrigerant

circuit shall 'be hermetic, thermally or mechanically sealed.

All refrigerant-containing components shall be securely

supported to minimize strain and vibration. A thermallysealed hermetic system shall consist of a compressor and

motor enclosed in a welded or brazed shell and connected within a refrigerant circuit wherein all refrigerant liquid or

gas containing parts shall be sealed to an extent that the

circuit cannot be opened without cutting or melting. A

mechanically sealed hermetic system shall contain a motorcompressor assembler enclosed either in (a) a welded or a

brazed shell or in (b) a gastight shell with mechanical

fastenings such as bolts or screws. In either type of

mechanically sealed hermetic system the cabinet and frame

shall be so designed that the motor-compressor assembly can

20 -

be readily removed for replacement or repair. Flared

or other compression-type fittings shall be limited to

not more than four readi ly-accessible joints at the

motor-compressor assembly. All other joints shall be

such that they cannot be opened without cutting or melting. A charging connection and valve, and. a dehydrator

shall be incorporated in the system.

3.9*3 Condensing Unit - The condensing unit shall be of

the air-cooled type, and shall consist of motor, compressor, condenser, control, and other necessary equipment *

3 .9* 3 .I Compressor - The compressor shall be properly

balanced and suitable for the refrigerant employed. The

oiling of all moving compressor parts shall be accomplished

automatically with provision for returning oil from suction

lines to housing or crankcase. The speed of the compressor

shall not exceed compressor manufacturer's published recommended speed for the intended service. Evidence shall be

provided that the selected speed has received field service

for a period of at least one year other than experimental

field service.

3. 9.3. 2 Air-Cooled Condenser - Air-cooled condensers shall

be constructed of brass, copper, or steel, hot-tin-dipped

or otherwise suitably protected on the outside after fabrication to resist corrosion. Fins, where used, shall be

soldered, welded, or mechanically bonded to the tubing to

insure permanent contact. Where the exterior casing of the

refrigerator or the metal surfaces of a duct at the back of

the refrigerator is used as extended condenser cooling surface the condenser tubes shall be securely bonded to the extended surface by mechanical or other means.

3 .9.3 .3 Refrigeration control - The refrigeration control

shall be a temperature control switch actuating the compressor motor. The temperature control shall be adjustable

in a range that permits control of the general food compartment temperature at any desired value from 37°F to 43 °F

when tested in accordance with. 4. 3 *5.2, The differential

of the temperature control shall be such that the temperature changes in the general food compartment and frozen

food storage compartment caused by cycling of the thermostat do not exceed the limits specified in 3. 5*1.1 during

no-load operation. The temperature control shall be readily
.
accessible for adjustment and servicing*

3.9,4 Refrigerant - The refrigerant in the hermetic compressor circuit shall be one of the following refrigerants:

Dichlorodifluoromethane CCj?2F2

Monochlorodifluoromethane CH Oil F 0

3.10 Motor and Control

3.10.1 Motors - Motors enclosed with compressors in gastight shells, shaded-pole motors, and direct-current

motors and all control equipment shall be constructed in

accordance with or equal to the best commercial practice

in effect on date of invitation for bids. All other alternating-current motors of fractional-horse-power size

shall comply with Federal Specification CC-M-636 . All

motors and electrical equipment shall be suitable for the

voltage and currents specified in the invitation to bid,

contract, or order. A transformer may be used for voltage

adjustment on hermetic systems for voltages other than

110 to 125 volts provided the combination of transformer

and other equipment meet all the requirements of this

specification. All wiring shall be protected from contact with oil or water in service, or shall be oil and

water resistant.

3.10.2 Motor Overlaod Protective Device - Compressor

motor shall be protected in case of failure of the starting mechanism, failure of the condensing medium, or excessive overload by an overcurrent or thermal protective

device of the automatic reset type. The device shall perform in accordance with the requirements of 3.5.5. Fuses

are not acceptable in lieu of this thermal-overload protective device. The starting mechanism shall be simple

in design and rugged in construction. Motor controllers

shall be provided where required.

3.10.3 Defrosting Heater - Electric heaters for defrosting,

if used, shall be so constructed and installed that the

user cannot come in contact with heated surfaces at a temperature above 130F at any time during the defrost cycle

during normal use of the refrigerator® The electric heater
:
22

shall be so constructed and installed that neither the frost

accumulation, the defrost water, or the food load can cause

an electric short to develop between the defrost heaters and

any metallic component inside the cabinet. The interior liner

and any cooling units that are defrosted by electric heaters

shall be adequately grounded to prevent hazard of electric

shock to the user. No terminals shall be located so as to

permit accidental contact by the user during normal use.

Electric heaters used for defrosting shall not exceed 1500

watts capacity.

3.10.4 Wiring and Accessories - All refrigerators shall b

completely electrically wired. All refrigerators having

electrical equipment wound for 250 volts or less shall be

equipped with an electric cord. The cord shall have an

attachment plug and shall extend at least 5 feet, but not

more than 9 feet, beyond the cabinet. The cord shall be

protected to prevent abrasion at the entrance to the cabinet

and shall be provided with adequate strain relief. For

electrical equipment wound for voltages over 250 , suitably

enclosed terminal blocks shall be provided for connection

to external circuits, unless otherwise specified.

3.11 Fire and Casualty Hazards

3.11.1 Underwriters ’ Laboratories Standards - The contractor

shall submit to the purchasing agency proof that the commodity

he furnishes under this specification conforms to the Standard

for Unit Refrigerating Systems of the Underwriters’ Laboratories, Inc., regarding fire and casualty hazards in every

detail except those in which requirements of this specification

are different from those of the above Standard. The label,

marker, listing or certified report of the Underwriters’

Laboratories, Inc., will be accepted as evidence of compliance with this requirement.

3 .11.1-. 1 Data From Other Laboratories - In lieu of Underwriters’ Laboratories evidence, the contractor may submit

evidence from other sources that his commodity conforms to

the Standard for Unit Refrigerating Systems of the Underwriters’ Laboratories, Inc., of the issue in effect on the

date of invitation for bids®

3. 11. 1*2 Precedence of Specification Requirements - Compliance with Underwriters’ Laboratories requirements regarding fire and casualty hazards does not absolve the con-
i dd t hsll£;!&r: • or-& br -tocr^enjpp a rO i. . >d-?

.

.

.

*
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tractor from complete compliance with the requirements of

this specification in order to secure the acceptance of his

commodity. In event of difference between any of the requirements of this specification and those of Underwriters’

Laboratories, Inc., the requirements of this specification

shall govern.

3,12 Instructions for Care and Operation - The contractor

shall furnish complete instructions for maintenance and

operation with each refrigerator, including complete lists

of replacement parts or assemblies, indicating manufacturer,

and manufacturer’s part numbers with contractor’s corresponding part numbers for dual identification.

3*13 Nameplate and Other Data.

3.13.1 Nameplate Data - The following shall be marked on

suitable name plate or name plates:

(1) Name of the organization sponsoring the completely

assembled refrigerator.

( 2 ) Manufacturer’s type number, model or catalog number,

and serial number.

(3) Voltage and kind of current; if alternating current,

the frequency and phases; if dual voltage, a connection

diagram for changing voltage shall be shown.

(4) The refrigerant used, expressed in chemical or other

descriptive terms, and amount of refrigerant required

to the nearest 1/4 pound.

(5) Factory test pressure of refrigerant system.

3 . 13*2 Component-parts Data - Compressors, controls, motors,

cabinets, etc. shall bear the name of the manufacturer (if

different from the organization sponsoring the completely

assembled cooler) and sufficient additional information for

replacement of parts or servicing,

3.13*3 Warning plates - Warning plates, if applicable, shall

be conspicuously mounted,

4. Sampling, Inspection and Test Procedures.

4.1 Manufacturer’s Routine Inspection and Test - It shall be
.
- 24

the responsibility of the manufacturer to supply refrigerators under contract that are in compliance with

all requirements of the specification. To assure that

production quality is maintained all refrigerators on

each contract shall, as a routine procedure, be inspected

by the manufacturer for fit, materials, finish, and general

conformity with the requirements of this specification.

Routine inspections are only intended for determination of general conformity with the requirements of the

specification that can be checked during assembly and by

visual observation after completion of the refrigerators.

Routine tests need not necessarily follow the test procedures of 4.3 of this specification.

4.1.1 Refrigerant Working Pressure - The refrigerant-containing system of each refrigerator to be furnished on

the contract shall not be damaged or leak when tested at

the pressures listed in Table III for the refrigerant

used.

Table III - Working Test Pressure

Refrigerant

Test pressure,

minimum

Highpressure

side

Lowpressure

side

Dichlorodifluoromethane, p.s.i.g. p. s. i.g.

CCC 2f 2- • 235 140

Monochlorodifluoromethane,

CHC£F2 335 235

4.2 Purchasers Inspection and Tests

4.2.1 Routine Production Inspections and Tests - Purchaser’s

routine inspection of refrigerators to determine the quality

control of manufacturing and assembly processes shall be

done at the manufacturer’s plant in the presence of a

representative of the purchaser before, during, or after

production is completed but before the refrigerators are

approved for shipment by the purchaser or his representative
:i$b io“!

: bt<

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• s.

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The extent of purchaser’s inspection and method of sampling

for routine inspection shall be established by the purchaser.

Purchaser’s routine tests shall also be made at the

manufacturer’s plant. The representative of the purchaser

may use the manufacturer’s routine tests described in 4*1

to evaluate the performance of the refrigerators to be

furnished under contract if these tests are performed in

his presence or if satisfactor3

^ records of the results of

these tests are available. Otherwise, one of each fifty

refrigerators or fraction thereof of each voltage, type, and

size offered for delivery shall be selected by the purchaser’s

representative and tested in his presence for compliance

with the operating requirements of paragraphs 3*5*1 through

3.5*5* All labor, equipment and apparatus required for the pro

duction inspection and tests shall be supplied by the manufacturer or contractor

4 . 2.2 Acceptance Inspection and Tests - Unless otherwise

specified in the invitation to bid, contract, or order, one

refrigerator of each type, size, and power supply shall be

tested to determine compliance with all construction and

performance requirements of the specification, invitation to

bid, contract or order. Performance tests shall be conducted

in accordance with 4*3*1 through 4*3*11* Acceptance inspections and tests shall be conducted at the manufacturer’s

works or at a Government laboratory as specified in the invitation to bid, contract, or order. All labor, equipment

and apparatus required to conduct the acceptance tests and

inspections shall be supplied by the contractor when tests

are conducted at his works or at another laboratory approved

by the purchaser when no testing facilities are available

at the manufacturer’s works. If the tests and inspections

are conducted at a Government Laboratory, the Government

shall supply the necessary labor, equipment, and apparatus.

In the event a refrigerator under test fails to meet the

requirements of this specification, the contractor may, at

his request, and at no cost to the Government, submit two

additional refrigerators or resubmit the original refrigerator readjusted or repaired for further tests. No more

than two resubmissions of readjusted or repaired refrigerators will be permitted. Failure of three specimens shall

constitute non-compliance with this specification.

In addition, the purchaser shall have the right to
rcis """ , i ' . . "V--
26 -

perform acceptance inspections and tests, at the purchaser’s

cost, on any or all refrigerators offered for delivery or

delivered under contract.. The Government shall notify the

contractor promptly of such additional acceptance tests.

Failure of such refrigerators to meet specification requirements with exceptions as noted in bid may result in

cancellation or adjustment of the contract and/or return

of refrigerators delivered under the contract.

All test specimens which do not meet specification

requirements with exceptions as noted in bid, shall, at

the purchaser’s option, be returned to the contractor

and, if returned, shall not be accepted for delivery

under contract.

When acceptance tests are conducted at a Government

laboratory, the scheduled delivery date(s) shall be

adjusted by the purchaser to compensate for the time

required for such testing®

4.3 Performance Tests

4.3.1 Conditions of Test - The conditions of test described

in 4. 3. 1.1 to 4. 3®1®9 apply to tests specified in 4*3.2

through 4»3®7.

4.3 .1.1 Test Specimen - The cabinet and refrigerating

mechanism shall be assembled and set up exactly as they

would be installed in service and as nearly as practicable in accordance with the intentions of the manufacturer

so far as stated or known. Ice trays and drip trays shall

be in their proper places during all tests. Containers

and covers, and food shelves shall not be removed,

4.3 .1.2 Run-In - Before starting the first performance

test the refrigerator shall be given a

Tt run-in’’ period of

not less than 24 hours. The ’’run-in’’ shall be made at

room temperature with the temperature control set at the

coldest position and the door(s) shall be closed.

4. 3. 1.3 Length of Test - In preparation for any operating

test the refrigerator shall be operated under specified

test conditions for a sufficient length of time to establish steady or repetitive state. Immediately after this

preliminarj?- period the refrigerator shall be operated

for the specified test period during which the desired elements of performance are determined by observation or measurement .
.

V* i »•
4«3el*4 Power Supply - Unless otherwise specified in the

invitation to bid, contract, or order, standard conditions of electric power supply for test purposes shall

be 115V ±2 volts at nominal 60 cycles. The characteristics of the actual power supply used for tests shall

be reported.

4 . 3 « 1®5 Mounting of Test Specimen - In all operating

tests each refrigerator shall be placed on a separate

solid-top platform with all sides open for free air circulation under the platform. The top of the platform

shall be 1 foot above the normal room floor and shall

extend at least 1 foot, but not more than 2 feet, beyond

each side of the refrigerator.

Circulation of air about the refrigerator under

test shall be restricted by vertical partitions. A rear

partition shall be placed adjacent to spacers, if provided

at the rear of the cabinet, but not less than 2-1/2 inches

from the rear wall of the cabinet. Vertical side partitions shall extend 1 foot forward from the rear partition and shall be placed 1 foot from the sides of the

cabinet. The partitions shall extend vertically from the

platform to a point not less than 1 foot above the top

of the cabinet or unit, whichever may be higher.

The refrigerator and partitions shall be placed far

enough away from all other objects in the hot room to

eliminate the danger of any partition being at a temperature other than the ambient.

The refrigerator shall be so placed or shielded as

to prevent direct radiation to or from the space-cooling

or -heating equipment, and windows in the test room shall

be provided with suitable radiation shields®

Air circulation in the room shall be such that the

specified uniformity of temperature distribution is

obtained. The refrigerator under test shall be shielded

from forced-air currents with a velocity above 50 feet

per minute.

4.3ol.6 Ambient Temperature - Ambient temperatures shall

be measured at points located 3 ft* above the platform and

10 inches from the
; ' f

... c n:

d i: " r : " f > s ic ; • ri " .
23 -

middle of each side and the front of the cabinet. Ambient

temperature at each point shall be maintained within ±1 F

of the specified values. This condition shall be maintained

during stabilization periods, as well as during actual test

runs.

The ambient temperature shall be measured with thermocouples, resistance thermometers, or glass thermometers.

The temperature- sensitive part of the temperaturemeasuring device shall possess, or shall be in good thermal

contact with, a metallic mass such as to bring about a

total heat capacity not less than 10 or more than that of

20 grams of water.

The temperature gradient In any foot of vertical

distance from the platform to a height of 7 feet shall not

exceed 0.5 F per foot,

4, 3, 1.7 General Food Compartment Temperature.- -The general

food compartment temperature shall be the average of three

temperatures observed at points designated as T^, T2 and To

in Figures 1 through 5« These temperature measurements

shall be taken midway between front and back of food storage

space. In case of interference, the temperature measurements

may be taken not more than 1 inch from the Indicated

positions. If the interior arrangements of refrigerators

do not conform with those shown in Figures 1 through 5>

temperature measurements shall be taken as nearly as

possible with the intent of this specification and tnese

locations reported.

Temperature of air in special purpose vessels (for

general food storage) such as are indicated In Figures 1

through 5 t shall be made as near as possible to the center

of the vessel.

Internal temperatures, other than frozen food compartment(s), shall be taken either with thermocouples or

with resistance thermometers. Each thermocouple or temperature-sensitive element of a resistance thermometer

shall possess, or shall be in good thermal contact with,

a metallic mass such as to bring about a total heat

capacity of not less than 10 or more than 20 grams of

water, and shall be supported In such a manner that there

will be at least 1/2 inch of air space separating the

thermal mass from direct contact with heat-conducting
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bO •H

NBS



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- 29 -

surfaces in the refrigerator® Leads from temperaturemeasuring devices shall be brought outside of the cabinet

in such a manner as to interfere as little as possible

with air seals.

4.3. 1.8 Temperature of Frozen Food Storage Compartment( s)

The temperature of each frozen food storage compartment

shall be the average of readings of 3 or 4 thermocouples

each embedded in the geometrical center of simulated

frozen food packages placed in each compartment, in

accordance with Figure 6. When more than one compartment

is provided the resiilts for each compartment shall be

reported separately. The average frozen food storage

compartment temperature shall be the arithmetical mean of

the temperatures given by the installed thermocouples.

The frozen food storage compartment ( s) under test shall be

loaded with packages of simulated frozen food which shall

practically fill the compartment( s) and shall be spaced

and distributed in accordance with Figure 6.

Sealed cardboard freezer packages approximately

4

H x 3"5/8" x 2" shall be used and shall contain a liner

or wrapper that makes them moisture and vapor proof. The

packages shall be filled to an overall package density of

35 pounds per cubic foot with saturated hardwood sawdust

soaked for 3 days in an aqueous solution of sodium chloride

with a specific gravity of 1.02 at 70 C F.

4.3. 1.9 Recording ©f Data. —Temperatures shall be recorded

graphically by instrument, photographically, or observed

and recorded by an operator, at intervals as specified

under 4.3.2 through 4.3.7. Temperature measurements shall

be accurate to 0„5F.

The operating time of the unit, where required, shall

be obtained by means of a synchronous, self-starting

electric clock or a similar time-integrator

4.3.2 No-Load Operating Tests. --The no-load operating test

shall be conducted in three parts (4.3.2.

through 4.3.2. 3}

in ambient temperatures of 90° F, 70° F and 110° F respectively, under general conditions of 4.3. For these tests the

ice cube trays shall be in place for all types of refrigerators and shall contain a charge of ice not less than

that specified in Table I. In addition. Type III and IV

refrigerators shall contain a full charge of simulated

HOUSEHOLD AUTOMATIC ELECTRIC REFRIGERATORS

(MECHANICALLY OPERATED)

THERHOCCKJHE LOCATIONS FOR DETERMINATION OF

FROZEN FOCD STORAGE CCMmRTMENT TEMHSRATDRES

l/4 nin.

Hote ; us© pint package *4x3 5/8 x 2

1 l -J ( L

*- Ice Trays — —1 J

t *

Ti x Ti

A *

**1

A B B L B B

L_

x

T^ )

t

3 x

Front View Side View

VERTICAL FROZE!! FOCD STCKAGE COMB^RTMEHT (Width less than 8 inches)

Hote : if one side of compartment is not refrigerated

Tj is to be located adjacent to that side.

VERTICAL FROZEH FOCD STORAGE CCM&imiSHT (Width greater than 8 inches)

Hote : loading of packages shall be distributed to provide equal

spacings"An (across width of campfc. ) or "B” (from front to back).

Fig . 6
'
frozen food as outlined in 4.3. 1.8.

Data to be recorded shall include:

Ambient temperature (4.3. 1.6)

General Food Compartment Temperature ( 4 . 3 . 1 . 7 ) Frozen Food Storage Compartment Temperature ( s

}

(4.3. 1.8)

Temperature (s) in special purpose vessels

( 4 . 3 . 1 . 7 ) Temperature control position

Percent operating time (4.3. 1.9)

In preparation for each of the three no-load operating tests, the thermostat shall be set at the position

determined by the procedure outlined in 4. 3® 2.1. Prior

to each no-load operating test, the refrigerator shall

be completely defrosted and dried. The ice-cube trays

filled as required with water or ice shall then be placed

in normal position, and, for types III and IV refrigerators,

the required simulated frozen food, preferably prefrozen,

shall be placed In the frozen food storage compartment( s )

.

The refrigerator shall then be operated for a stabilizing

period of at least 6 hours at test conditions after the

ice charge is frozen, the average general food compartment

temperature has indicated repetitive values within 0.5 F

for two thermostat cycles, and, for types III and IV, the

average frozen food temperature has also indicated repetitive values within 0.5 F for two thermostat cycles.

Each test shall commence without interruption at the

end of the stabilizing period, shall be continued for a

period of at least 12 hours and shall cover an equal

number of off-periods and on-periods of compressor operation. Refrigerator door(s) shall not be opened during

the stabilizing period or test period.

Refrigerators shall, if practical, be operated without any defrosting during the no-load operating tests.

Refrigerators with automatically-initiated defrosting

means may be defrosted, if It is not feasible to prevent

defrosting or, if the average general food compartment

temperature would be adversely affected by preventing

the defrost. If defrosting is permitted the temperatures

observed during defrosting shall be included in the

overall average for the no-load operating test.

- 31 -

Temperature observations shall be made continuously

or at equal intervals not greater than 15 minutes.

Reported temperatures shall be the arithmetic average of

all readings taken at equal time intervals.

4.3.2. 1 No-Load Operation at 90°F Ambient Temperature.--

The first no-load operating test shall be conducted at 90°F

ambient temperature. In preparation for this test the

temperature control shall be set to control the average

general food compartment temperature at 39° F -1°F based

on the arithmetic average of readings taken at 5 minute

intervals for at least two complete cycles or for at

least one hour whichever is the longer after repetitive

temperature conditions have been ouserved for at least

two complete cycles. Normal ice and frozen food loads

shall be in position when thermostat setting is determined.

4. 3. 2. 2 No-Load Operation at 70° F Ambient Temperature.

The second no-load operating test shall be conducted at

70° F ambient temperature. The temperature control shall be

set at the same position as for the test at 90° F ambient

temperature.

4. 3. 2. 3 No-Load Operation at 110° F Ambient Temperature.

The final no-load operating test shall be conducted at

110° F ambient temperature. The temperature control shall

be set at the same position as for the test at 90° F

ambient temperature.

4.3.3 Ice-Making Test. (See 3. 5. 2) --The refrigerator shall

be set up under the general conditions of 4.3.1 with the

ambient temperature controlled at 90° F -2F. The general

food compartment and the frozen food storage compartment

shall be empty except for the ice trays.

4. 3. 3.1 Preliminary Operation. —In preparation for the

ice-making test the refrigerator shall be operated for a

period of eight (b) hours with the temperature control set

to maintain an average general food compartment temperature

of 39° F ±1F as described in 4.3.2. 1. The ice trays shall

be left out of the refrigerator during this preliminary

period. The evaporator shall be free from frost and the

interior of the cabinet shall be dry at the beginning of

the d-hour preliminary period of operation.

4. 3. 3. 2 Ice Tray Loading. —At the end of the d-hour pre-

- 32 -

lirainary period each ice tray shall be filled with water

at 90° F ±£F fco a. level 1/8- inch from the top with the grids

in place and the weight of water determined* Enough trays

shall be used fco hold a weight of water equal to or greater

than the minimum ice capacity shown in Table 1* The ice

trays shall be inserted quickly into the lea-making com*

parfcment in their normal locations, after wetting the

surfaces of the. cooling unit on which the trays rest to

insure good heat transfer*

4»3«3*3 Freezing period. --After inserting the ice trays

in the refrigerator the temperature control shall be set

at the coldest setting that permits cyclic operation

(not shunted) and left at this setting during the 6-hour

test period. The door shall be left closed during the

entire 6*hour test. Six hours after closing the door at

the beginning of the test the Ice trays shall be removed

and inspected to determine whether or not all of the charge

has been frozen.

4.3*4 Defrost Test. -“The refrigerator shall be operated

•under the general conditions of 4.3*1. The test room shall

be maintained at a temperature of 90° F -2°F and a relative

humidity between 80 and 85$ « The temperature control shall

he set to control the general food compartment at 39° F -1°F

as specified in 4.3*2. 1. The refrigerator shall contain

the required ice charge and Type III and IV refrigerators

shall be loaded with simulated frozen food as specified

in 4. 3.1. 5,

4.3.4. 1 Type I, Manually- initiated Defrost* --The refrigerator shall be defrosted and the evaporator and cabinet

interior wiped dry. With ice or water in the ice cube

trays the refrigerator shall be placed in operation and

observed until the water is frozen and repetitive temperatures of the general food compartment have occurred for

at least two thermostat cycles as indicated by temperature

observations taken at equal intervals not greater than 13

minutes. Beginning at this time a frost accumulation

period shall be started. For 20 hours the refrigerator

door shall be opened wide for a period of 30 seconds 4

times at the beginning of each hour at 5 minute intervals,

for a total of 80 door openings in the 20 hour period*

Temperature observations of the general food compartment

shall be made at equal intervals not greater than 30

minutes one of which shall be made just prior to the first

door opening each hour. At the end of the twentieth hour
- ' . i I

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.

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- 33 -

the refrigerator shall be defrosted, with the door closed

and ice trays in place, by manually setting the temperature

control in the defrost position*, During the defrost cycle

and the operating period following, temperature observations

of the general food compartment shall be made at equal

intervals not greater than 15 minutes * When the defrost is

completed as Indicated by the temperature control calling

for refrigeration, the evaporator shall foe examined and the

degree of defrosting determined. The refrigerator shall

then be operated without manual readjustment of the temperature control until the general food compartment temperature has been observed for at least two thermostat

cycles or at least one hour, ’whichever is longer, to permit

determination as to whether at least limited refrigeration

is provided.

4„3 tt 4„2 Type III Manually- initiated Defrost. “-The refrigerator

shall be operated under conditions of 4,3*1 and 4.3.4, Preliminary to the main defrost test a defrost cycle shall be

initiated manually after approximately 4 hours of operation.

At the conclusion of this defrost cycle a period of frost

accumulation shall be started. The refrigerator door shall

be opened wide for a period of 30 seconds 4 times per hour

at the beginning of each hour at 5 minute intervals. Temperature observations of frozen food storage compartment and

general food compartment shall be made at equal intervals

not greater than 30 minutes, one of which shall be made just

prior to the first door opening each hour. The door openings

shall be continued for 20 hours and at the end of the

twentieth hour a defrost cycle shall be manually initiated.

Temperature observations shall be made at not greater than

5 minute intervals throughout the defrost cycle and the temperature rise of the frozen food and general food compartment

shall be based on the highest average temperature observed

during the defrost and the average temperature

observed immediately following initiation of defrost. The

door shall not be opened during this defrost cycle or during

a recovery period which shall follow Immediately. The

recovery period shall commence when the general food compartment begins to drop in temperature and shall be continued

for 4 hours, during which time temperature observations shall

be made at equal intervals not greater than 30 minutes. The

20-hour period of door openings shall then be repeated and

the refrigerator again defrosted by manual initiation exactly

as before. Immediately after this defrost cycle, the refrigerator shall be opened and examined for degree of defrosting accomplished.
> :

.
- 34 -

4. 3.4. 3 Type II & IV Automatically- initiated Defrost.--

The refrigerator shall be operated under conditions of

4,3*1 and 4.3.4, Preliminary to the main defrost test

such mechanical operations (as timer adjustment, door

openings, etc.) shall be applied as are required to cause

an automatic initiation of a defrosting cycle after approximately 4 hours of operation. At the conclusion of this

defrost cycle a period of frost accumulation shall be

started. The refrigerator door shall be opened wide for

a period of 30 seconds 4 times per hour at the beginning

of each hour at 5 minute intervals. Observations of

frozen food storage temperature (for Type IV) and general

food compartment temperature shall be made at equal intervals not greater than 30 minutes, one of which shall be

made just prior to the first door opening each hour. The

door openings shall be continued for 20 hours and until

the first automatically-initiated defrost occurs following

the 20 hour period. Observation of frozen food and general

food compartment temperatures shall be made at equal Intervals not greater than 5 minutes throughout this defrost

cycle and the temperature rise of the frozen food and

general food compartment shall be based on the highest

average temperature observed during defrost and the average

temperature observed immediately following initiation of

defrost. If initiation of the first defrost following the

end of the 20-hour frost accumulation period occurs during

a door-opening period, the door shall be closed immediately and shall not be opened during this defrost cycle or

during a recovery period which shall follow. The recovery

period shall commence when the general food compartment

temperature begins to drop and shall be continued for four

hours, during which time temperature observations in the

general food and drozen food storage compartments shall

be made at intervals not greater than 30 minutes. The

20-hour period of door openings shall then be repeated

exactly as before and continued until the first automatic

Initiation of defrost after the 20-hour period. Immediately following this defrost the refrigerator shall be opened

and examined for degree of defrosting accomplished.

If a refrigerator that defrosts on every off-cycle

does not cycle during the 20-hour frost accumulation period,

the door openings shall be discontinued at the end of this

20-hour period and the first defrost which then occurs shall

be observed. The refrigerator shall then be operated for

a recovery period of 4 hours as outlined in the preceding

- 35 -

paragraph. The 20-hour period of door openings shall then

be repeated exactly as before and a defrost cycle allowed

to occur thereafter, followed immediately by an Inspection

of the cooling surface to determine the degree of defrosting accomplished. Observation of frozen food and general

food compartment temperatures shall be made in the same

manner as outlined in the preceding paragraph.

If a refrigerator defrosts 10 times before the end

of the 20-hour frost accumulation period, the door openings

shall be discontinued after the tenth defrost and the

refrigerator permitted to recover for 4 hours. The test

shall be concluded by inspecting to determine the degree

of defrosting accomplished immediately following the first

defrost after the 4-hour recovery period. Temperature

observations during this test shall be made in the same

manner as outlined in the first paragraph of 4. 3.4® 3. The

temperature rise of the general food and frozen food storage

compartments during defrost shall be based on the highest

average temperature observed during the tenth defrost and

the average observed immediately after initiation of the

tenth defrost.

4.3*5 Temperature Control Test? (See 3.5*1. 1 and 3 . 5 * 1 . 2)

4.3.5* 1 Temperature differential. --The general food

compartment temperature shall be determined as the average

of the temperatures Tq, T2 ? and in Figures 1 through 5

and the frozen food storage compartment temperature shall

be determined as the average of the 3 or 4 thermocouples

in this compartment observed at equal time Intervals of

15 minutes or less during the three no-load operating

tests described in 4.3.2. 1 to 4, 3 ,2. 3 . The temperature

differential in each compartment for each test shall be

the difference between the mean of the two highest and

two lowest average values determined in the above manner.

4. 3. 5*

2

Temperature Range. --The refrigerator shall be

operated under the general conditions of 4.3*1 with the

ambient temperature controlled at 90° F ±2F. In two

successive tests with the temperature control set at the

lowest and the highest settings that result in cyclic

operation (not shunted), respectively, the refrigerator

shall be operated until repetitive temperatures are observed in the general food storage compartment during

successive thermostat cycles. The refrigerator shall be

- 36 -

operated for a test period of two hours or two complete

thermostat cycles whichever is longer after repetitive

temperatures are observed for each control setting.

Temperature observations shall be made continuously or

at equal time intervals not greater than 15 minutes in

the general food storage compartment during the test period

and the arithmetic average of all readings so taken shall

be the average general food compartment temperature for

each control setting.

4.3.6 Sweating Test (See 3.5.4). The refrigerator shall

be operated for a period of not less than eight (8) hours

at a control setting that produces an average general food

compartment temperature of 39 °F ±1F as determined in

4.3.2.

1

and in an ambient temperature of 90 °F -IF and

a relative humidity maintained between 73 and 7&$ at all

times.

At the end of the eight“hour test the entire exterior

of the refrigerator including door latch, hinges, and

visible portion of the door gasket shall be inspected for

condensation visible to the eye or detectable by wiping

with the fingers.

4.3.7 Motor Overload Protection Test.

4.3.7. 1 Motor overload protective device. “-Each sample

refrigerator shall be operated on a line voltage as

specified -2 volts In an ambient temperature of 90° F ±2F

with the heat transfer from the air-cooled condenser

restricted sufficiently to cause the compressor motor

overload protective device to function. This test shall

be continued until four successive measurements of compressor winding temperature at time of overload trip- out

indicate repetitive values.

4. 3 . 7 . 2 Failure of starting mechanism.—The starting winding of all single-phase compressor motors and one power

lead to all three-phase compressor motors shall be disconnected and specified voltage ± 2 volts applied to the

service connection of the refrigerator. This test shall be

continued for two hours or until four successive measurements of compressor-motor running-winding temperatures

at time of overload trip-out indicate temperature equilibrium. (note. —For three-phase motors the temperature

observations shall be made of the energized winding.)
• .

.

:• - -

- -

t -i
- 37 - 4.3®7®3 Locked-rotor test of fan motors.—Fan motors If used*

shall be energized with the rotor locked for a period of

two hours or until four successive readings indicate that

the temperature of motor windings has reached a steady state.

The resistance of the fan-motor windings shall be measured

each time the overload protective device functions* or at

15-minute Intervals if the motor is not equipped with an

overload protective device.

4»3®7<>4 Temperature of motor windings. -The temperature of

the compressor and fan motor windings shall be determined

by the following formula for copper conductors 1

th = (390+tc dL - 390

Kc where Is the temperature of the motor windings when

disconnected from the circuit by the overload

device* °P,

tc is the temperature of the motor windings when

the motor is cold and In equilibrium with the

ambient temperature* °F.

R^ is the resistance of the motor windings hot.

Rc Is the resistance of the motor windings at

temperature tc. The temperature of the compressor and fan motor windings

shall not exceed 302° F. based on the average of the four

highest observations taken.

4. 3® 8 Moisture content of refrigerating system.—After at

least 1 hour of continuous operation of the motor-compressor unit in an ambient temperature of 90°.F. with the

door open and with the refrigerator empty* the refrigerator shall be disconnected from the electric supply and

allowed to stand for 1 hour with the door ©pen. A sample

of refrigerant vapor shall then be withdrawn from the lowpressure side of the system and its moisture content

determined by either the gravimetric method employing

P2O5 or the electrical method employing hygroscopic film

for compliance with the moisture content requirements of

3 * 6 .

- 3b -

4.3.9 Drop Test. --The drop test required in paragraph

3.4.1 shall be conducted in the following manner:

All shelves shall be loaded at 12 pounds per square foot,

with the weight generally distributed over the shelf area.

The material used for shelf loading shall either be nonrigid or shall consist of increments, each covering not

more than 10$ of the particular surface under test. All

trays (including special purpose vessels such as ice-cube

trays, erispers, drip trays, butterkeepers, etc.)

furnished with the refrigerator, which are normally used

for storage of food items, shall be filled to the equivalent of 50$ of normal capacity by volume with suitable

materials, not in liquid form, having an overall density

of 35 pounds per cubic foot. One side of the refrigerator

at a time shall then be raised three inches off a level

concrete floor and be allowed to drop free in the following order, left side, rear, right side, front. The refrigerator shall be held in the elevated position for the

drop test by a single support which can be withdrawn so

the refrigerator is not hampered in its free fall or

caused to fall in a plane other than parallel to the

specified direction of fall.

4.3.10 Tests for porcelain enamel.

4.3.10.1 Thickness of enamel.—The thickness of the

porcelain enamel shall be measured at three spots with a

magnetic thickness gage or other suitable means accurate

to plus or minus 0.001 inch, and the average thickness

at the three measured spots shall be taken as the thickness of the enamel for the piece. (See 3. 8. 4. 2.1)

4.3.10.2 Reflectance test. --The reflectance of white

porcelain enamel shall be determined on an instrument

having the characteristics of the Multipurpose Photoelectric Ref lectometer, using the green filter, as

described in Research Paper RP1345 published in the

National Bureau of Standards Journal of Research, 25

(5) 581—618 (1940), or by the integrating sphere method

described in the Illuminating Engineering Society Transactions for 1920 or the Journal of the Optical Society

of America, 28, 372 ( 1938 ). As an alternative, the

reflectance may be compared visually to a plate having

the minimum allowable reflectance, such plate having

been previously standardized with a ref lectometer . In

case of doubt as to whether the specimen meets the

- 39 “

requirements* reflectometer measurements shall be used.

(See 3. 8. 4. 2.1).

4.3® 10.3 Ac id-res! stance test (for porcelain-enameled

liners only)»--A solution containing 10 grams of crystalline citric acid per 100 milliliters of distilled water

shall be prepared not moa@ than 24 hours prior to use.

The test shall be made on a horizontal (bottom) interior

surface of the liner. The area to be tested shall be

cleaned by washing with soap and water, rinsing, and drying with a clean towel. With the specimen and acid

solution at 80 0 ±10°F„, several drops of acid solution

shall be placed on the specimen to form a pool and

immediately covered with a 1-inch inverted watch glass.

After 15 minutes of treatment, the watch glass shall be

removed and the acid solution immediately rinsed from the

test surface. The specimen shall be dried with a clean

towel by blotting (not rubbing). Place a small light

source* such as a frosted lamp bulb, inside the liner so

its reflected image can be observed as a highlight in the

untreated area of the liner bottom, the line of vision

being within 45 0 of the perpendicular to the surface.

Focus the eyes on the image of the light source, not the

enamel surface. Then shift the head or the light source

just sufficiently to bring the image of the light source

into the treated area observing it as it passes the

boundary line. Any color difference in the enamel due to

staining shall be Ignored* but if a definite blurring

of the image is observed as it passes from the untreated to

the treated area* or if the image disappears* the specimen fails the test* otherwise it passes. (See 3.8. 4. 3).

4.3.11 Tests for plastic parts.

4.3.11.1 Styrene and laminated thermosetting plastics

Thermal expansion of door liners. Plastic door liners

shall not crack, craze or become permanently distorted

when subjected to the following tests:

1. The assembled door shall be permitted to come

to thermal equilibrium at 150°F and then at 0°F.

The door may be removed from the refrigerator

for this part of the test.

2. The door shall then be reinstalled on the refrigerator, closed and permitted to come to

- 40 -

steady state with the interior refrigerator

temperature at the lowest value obtainable with

continuous operation of the refrigerating unit

in an ambient temperature of 110° F.

5. Preparation for Delivery

5.1 Packing, —Refrigerators , including electrical equipment,

shall be packed for shipment to permit acceptance by carrier

for transportation at the lowest applicable rate, and to

afford maximum: protection from normal hazards of transportation. Packing shall be in accordance with Federal

Specification RR-P-0021.

5.2 Packaging. --Packaging shall be in accordance with

Federal Specification RR-P-0021. When crates are used,

refrigerators shall be provided with protective covering

to guard against damage from dust and moisture.

5.3 Marking. --Marking shall be in accordance with Federal

Specification RR-P-0021.

5.3.1 Shipping containers shall be marked with the name

of the commodity, the type, the size, and the quantity

contained therein, as defined by the contract or order

under which shipment is made, the name of the contractor,

and the number of the contract or order.

5.3.2 In addition to the above marking, cases or crates

containing motors, controllers, and spare parts and tools

for same, shall be marked to show the applicable voltage

and current characteristics.

6. Motes

6.1 Ordering data. --Purchasers should exercise any desired

options offered herein and should specify the following,

as applicable;

(a) Required type and size (see 1.2.1, 1.2.2 and

Table I.

(b) Required voltage and kind of current, including

phases, and frequency If alternating current.

(c) Limiting dimensions (if different from those

required by table I).

- 41 -

(d) Components and equipment not required by this

specification, (see 3.6).

(e) Exterior casing and interior liner materials

permitted or desired if other than steel. (See

3.6.4. 1 and 3. 6. 4. 3).

(f) Color of exterior casing, interior liner and

door liner, if particular color(s) are desired

other than as specified. (See 3. 6.4. 2, 3. 8. 4.

and 3. 8.4.4 )

(g) Required door swing, right or left. (See 3.8.6).

(h) Type of refrigerating system:

For 50 or 60 cycle alternating current specify type of

hermetic system desired if both are not acceptable. (See 3.9.2). For direct current or other

than 50 or 60 cycle alternating current specify

open type system.

(i) Sampling procedure for acceptance inspection and

tests if different from that specified in 4.2.2.

Specify where acceptance inspection and tests

shall be made.

(j) Whether services of an installation mechanic are

required. (See 6.6).

(k) Type of packaging and packing required, domestic

or overseas. (See 5.1 and 5.2).

(l) Designate special features required, such as top

or bottom location of frozen food compartment,

defrosting of frozen food compartment if separate

cooling surfaces are provided for general food

and frozen food compartments, special vessels,

etc., which are available in some models but are not

covered as options by this specification.

6.2 Pre-award examination. --Purchasing officers may, at

their option, include the following paragraph in their

Invitation to bid, contract, or order:

Pre-award examination. --The purchaser shall have the

right as part of the pre -award survey, to require any

42

bidder upon twenty days 1 notice to make available to the

purchasing officer or his representative, a sample of each

item bid upon to determine compliance with the specifications. If the samples offered for examination are found

not to be in conformity with the specifications, this may

result in the rejection of an otherwise acceptable bid.

Examination of samples will be made at the factory designated by the bidder in his bid, unless otherwise specified

in the invitation to bid, contract or order.

6.3 Deviations from requirements . --Purchasing officers may,

at their option, include the following paragraph in their

invitation to bid, contract, or order:

Deviations from requirements . --Any deviation from

the general requirements and construction requirements

(section 3) which provides quality equal or superior to

the requirements of this specification, and which is noted

as an exception by the contractor in his bid, will be given

consideration. The burden of proof of such equal or

superior quality shall rest on the contractor and the

purchasing officer shall have the option of determining the

validity of such proof by any means suitable to him.

6.4 Manufacturer’s agents. —Bidders should be required to

supplement their bids with a list giving the names of the

distributors or agents who will furnish the service referred

to in 6.6 to the various stations listed in the invitation

to bid.

6.5 Service guarantee . --It is suggested that purchasing

officers include the following clause in their invitation

to bid, contract, or order:

Service guarantee. --The contractor guarantees the

equipment against defective material, workmanship, and

performance for a period of one year, said guarantee to

run from date of acceptance of the equipment by the Government. The contractor agrees to furnish, without cost to

the Government, replacement of all parts and material

which are found to be defective during the guarantee period.

Replacement material and parts shall be furnished to the

Government at point of Installation if installation is

within the continental United States, or f.o.b. the continental United States port to be designated by the purchasing

officer if Installation is outside of the continental United

States. Cost of installation of replacement material and

parts shall be borne by the Government.

- 43 - 6.6 Installation supervision and adjustment. —Purchasing

officers may, at their option, include the following paragraph in their invitation to bid, contract, or order:

The contractor shall provide the services of a representative to make all necessary adjustments of equipment

at the time of installation.

Patent notice. --When Government drawings, specifications

or other data are used for any purpose other than in connection with a definitely related Government procurement

operation, the United States Government thereby incurs no

responsibility nor any obligation whatsoever; and the fact

that the Government may have formulated, furnished, or in

any way supplied the said drawings, specifications, or

other data, is not to be regarded by implication or otherwise as in any manner licensing the holder or any other

person or corporation, or conveying any rights or permission

to manufacture, use, or sell any patented invention that

may in any way be related thereto.

7. Departmental Requirements*

7.1 Departmental specifications and other publications.

The following departmental specifications and other publications of the issues in effect on date of invitation to

bid, and special requirements, shall form a part of this

specification, and shall be applicable to purchases made

under this specification by the respective departments.

The departmental requirements as listed in Federal Specification AA-R-211c are not included in this proposed draft.

The latest departmental requirements available for a

similar item (Federal Specification 00-C-566c, January,

1954, Dispenser, Drinking Water, Mechanically-cooled)

have been edited and one Military Specification (MIL-P12323A, Packaging of Refrigerators) has been added for

inclusion in this proposed draft. This section should be

modified,^J.f necessary, in light of the latest Military

packing, packaging and marking requirements, and MIL-PI2323A should be properly referenced.

44

7.2 Army1 , Navy and Air Force.

7.2.1 Applicable specifications and other publications:

Federal Specifications:

NN-B- 591"-Boxes ; Fiberboard, Wood-Cleated

(for Domestic Shipment). 2^ NN-B-601- -Boxes ; Wood-Cl^ated-Plywood,

for Domestic Shipment.'*

NN-B-621--Boxes; Wood., Nailed and Lock-Corner.

UU-P- 268- -Paper, Kraft, Wrapping (With

Conservation Provision).

UU-T- 111- -Tape, Paper, Gummed (Sealing and Securing).'

UU-T- 116—Tape , Paper, Gummed, Water-Resistant.

LLL-B-63 1 - -Boxe s : Fiber, Solid (for Domestic Shipment) .

*Applicable to Navy purchases only.

^Applicable to Army purchases only.

^Applicable to Air Force purchases only.

^Applicable to Army and Air Force purchases

^Applicable to Navy and Air Force purchases

Military Specifications:

JAN-P- 103- -Packaging and Packing for Overseas - Shipment- -Boxes 1 Wood-Cleated, Solid Fiberboard. 5

JAN-P-104- -Packaging and Packing for Overseas

Shipment—Crates, Sheathed, Wood, Nailed.

JAN-P- 105- -Packaging and Packing for Overseas

Shipment- -Boxe 3 ; Wood, Cleated, Plywood.

JAN-P- 106 --Packaging and Packing for Overseas

Shipment- -Boxes ; Wood, Nailed.

MIL-P-X l6- -Packaging and Packing for Overseas

Shipment--Preservation, Methods of .5

JAN-P- 125- -Packaging and Packing for Overseas

Shipment- -Barrier-Materials, Waterproof, Flexible.

JAN-P-127“- “Packaging and Packing for Overseas

Shipment- -Tape, Adhesive, Pressure-Sensitive,

Water-Resistant •

JAN-P-132-~Packaging and Packing for Overseas

Shipment—Crates; Unsheathed, Wood. Nailed (for

Maximum Net Load of 2,500 Pounds). 3

MIL-A- 140 - - Adhe s ive , Water-Res^ s tant

,

Waterproof Barrier-Material .

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only.

only.
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.

•

.

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MIL-M-79H—Mark!ng, Identification-, of Aeronaut i c a1

Equipment, Assemblies, and Parts.

MIL-P-12323A—Package ng of Refrigerators

Navy Department Specifications : General Specifications for Inspection of Material • 1

Military Standards:

MIL-STD- 105—Sampling Procedures and Tables for

Inspection by Attributes.

MIL-STD- 129 - -Marking of Shipments

(Copies of specifications . and standards required bycontractors in connection with specific procurement

functions should be obtained from the procuring agency or

as directed by the contracting officer.)

7.2.2

Army . 3

7.2.2.

Preservation. --None required. , 7.2.2.

Packaging.

7 . 2. 2. 2.1 For domestic and overseas shipment.

7 .2. 2. 2. 1.1 Fixtures ."-.Detachable fixtures that protrude

from the exterior surface of the refrigerator and that

might cause damage or be damaged during shipment shall be

removed and cushioned with cushioning fiberboard container

constructed to fit the contents in a compact manner in

accordance with style RSG of Federal Specification LLL-B631. The container shall be sealed with gummed paper tape

conforming to Federal Specification UU-T-111, minimum

width 2 inches. The container shall then be secured in a

fixed position within the refrigerator cabinet.

7 . 2. 2. 2.1.2 Floating mechanism. “-“Floating mechanisms shall

be secured immobile to prevent vibration and subsequent

damage during handling and shipment.

7 . 2.

. 3 Packing.

7 . 2. 2.

3.1

For domestic and overseas shipment.

- 46 -

7. 2. 2. 3. 1.1 Cushioning. --The refrigerator shall be cushioned

and held securely within the container by placing edge pads

over the full length of all edges of the refrigerator. The

edge pads shall be built up of double-face corrugated

fiberboard, extending 3 inches in from the edge on both

surfaces of the refrigerator and to a minimum thickness to

provide a tight pack and a 1-inch clearance between the outermost projection of all surfaces of the refrigerator and all

adjacent inside surfaces of the container. For overseas

shipment, the cushioning material shall be water resistant.

T.2.2. 3. 1.2 Protection of finished surface. --One of the

following shall be placed between the fiberboard pads and

the finished surfaces- of the refrigerator:

a. A sheet of kraft paper weighing not less than

30 pounds per ream (24 by 36 - -500) dry waxed on both sides

with a total of not less than 8 pounds nor more than 12

pounds per ream (24 by 36- -500 ) of fully refined wax having

a melting point of not less than 132°F. Total weight of

finished sheet shall be not less than 40 pounds per ream

(24 by 36--500)

„

b„ A sheet or pad of creped cellulose wadding having

a thickness of not less than 0.14 inch, surfaced on the

side contacting the fiberboard pads with kraft paper having

a minimum basis weight of 30 pounds per ream (24 by 36-500).

7.2. 2.3. 1.3 Containers . --Exterior containers shall be constructed according to table IV, except the bases of cleated

fiberboard or cleated plywood containers shall be constructed of two nominal 1- by 4- inch headers (end floor

members) secured in a right-angle position to two nominal

2- by 4-inch skids. Bases for overseas containers shall

have a sheet of plywood, as required in the applicable

specification, between the skids and headers. The side

panels of the containers shall extend down to within 1/4

inch of the bottom of the skids and shall be secured to

the sides of the skids. The end panels of the containers

shall rest on top of the skids between the side panels

and shall be secured to the edge of the headers (end floor

members). Type C untreated plywood shall be used in overseas container body material.
•

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.

•

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Table IV. --Exterior container requirements

Specification

No.

ClassificationShipment

NN-B-591 Style A--

Domestic (Weight of

contents to 400 lbs.)

NN-B-601 Style A--- Domestic (Weight of

contents to 500 lbs.)

JAN-P-104— Type I---- Domestic (Skid base'

Weight of contents exceeding 500 lbs.)

JAN-P-105 Style A-— Overseas (Weight of contents to 500 lbs.)

JAN-P-104- — Type I---- Overseas (Skid baseWeight of contents exceeding 500 lbs.)

When the weight of contents of containers constructed

in accordance with Military Specification JAN-P-104 do not

exceed 1,000 pounds and the inside dimensions do not exceed

4 feet long, 3 feet wide, and 3 feet 6 inches deep, the

frame members of the sides, ends, and top, shall be of

1- by 4-inch material.

Top coating material and waterproof barrier material

shall not be required on the top of crates for domestic

shipment

7. 2. 2. 4 Marking. —Each exterior container shall be marked

in accordance with Military Standard MXL-STD-129, and in

addition, arrows shall be prominently painted or stenciled

on the two sides and two ends of the container indicating

the position in which the container shall be handled In

transit and storage. The word "UP" shall appear at the

point of each arrow in letters not less than 2 inches high.

7. 2. 2.

Sampling. --Sampling shall be conducted in accordance

with Military Standard MXL-STD-105.

7.2.3 Navy.

7.2.3.

Preservation. --All exposed uncoated metal surfaces

shall be cleaned with petroleum solvent and when dry, coated
. - -:.z X

'• .
- 48 -

with rust-preventive compound conforming to type P-2

of Military Specification MIL-P-116. All inlets, outlets,

and openings into motors over electric switches shall be

sealed with tape conforming to the requirements for type I,

grade B, of Military Specification JAN-P-127.

7 . 2. 3 .

Packaging.

7 . 2. 3 . 2.1 For domestic shipment (immediate use) .--Commodity

shall be protected by a shroud of 60 -pound-basis-weight

kraft paper conforming to Federal Specification UU-P-268.

The overlaps shall be sealed with gummed paper tape, 2-1/2

inches wide and conforming to the requirements of Federal

Specification UU-T-116.

7 . 2. 3 . 2. 2 For overseas shipment. —Commodity shall be protected by a shroud of waterproof barrier-material conforming

to Military Specification MIL-A-140.

7. 2. 3. 3 Packing.

7 *2. 3 . 3.1 For domestic shipment (immediate use). —When

specified by the procuring agency, the subject commodity

packaged as described in 7 . 2. 3 .2.1 shall be packed in

substantial commercial exterior containers conforming to

the Consolidated Freight Classification Rules in effect at

time of shipment. The gross weight of wood boxes shall not

exceed approximately 200 pounds, except where the weight

of an individual item exceeds this amount. The gross

weight of fiberboard boxes shall be subject to the weight

limitations indicated on the box maker's certificate.

7. 2. 3 . 3 .

For overseas shipment. --Commodity, prepared as

specified in 7 . 2 . 3.1 and 7 . 2 . 3.shall be individually

secured by blocking, bracing, and cushioning in containers

constructed to fit the contents in a compact manner in

accordance with the requirements of Military Specification

JAN-P-103 » style A or B; JAN-P-104; JAN-P-105, style A or

B; or JAN-P-106, style 2 or 4. Only one type and style of

container shall be used on any one shipment.

7.2.3.^ Marking. --In addition to any special marking required by the contract or order, shipments shall be marked

in accordance with Military Standard MIL-STD- 129 .

7 . 2. 3 . 5 Ordering data. --Procurement documents should specify

whether domestic or overseas shipment is required.
'• ' - ,• . : •

..
- 49 ~

7.2. 3®

Inspection procedures. --General inspection procedures shall be in accordance with General Specifications

for Inspection of Material.

7 . 2.3*7 Bureau of Ships. --Such purchases will be made under

the applicable Military Specification.

Y.2„3»8 Other Naval activities . --Such purchases will be

made under this Federal Specification.

7.2.4 Air Force.

7.2.4.

Preservation.

7. 2.4.1.

For domestic shipment. --Commercial preservation

will be acceptable.

7. 2 .4*1,

For overseas shipment. --All exposed uncoated metal

surfaces shall be cleaned with petroleum solvent and when

dry* coated with rust-preventive compound conforming to

type P-2 of Military Specification MXL-P-116. All inlets*

outlets* and openings into motors over electric switches

shall be sealed with tape conforming to the requirements

for type I* grade 3, of Military Specification JAN- P-127.

7. 2. 4.

Packaging.

7 .2. 4. 2.1 For domestic shipment. --Commodity shall be protected by a shroud of 60-pound-basis- weight kraft paper

conforming to Federal Specification UU- P-2.68. The overlaps

shall be sealed with gummed paper tape* 2-1/2 inches wide

and conforming to Federal Specification UU-T-111.

7. 2. 4. 2.

For overseas shipment. --Commodity shall be protected by a shroud of waterproof barrier-material conforming

to Military Specification JAN-P-125. The overlaps shall be

sealed with adhesive conforming to Military Specification

MIL-A-140.

7-2.4,

Packing.

7 .2. 4. 3.1 Bor domestic shipment . --Commodity, prepared as

specified in 7. 2.4.1, shall be individually secured by

blocking, bracing, and cushioning In containers constructed

to fit the contents in a compact manner and in accordance

with the requirements of Federal Specification NN-B-591*
'.*•

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'

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:

.

; t:vi
- 50 -

style A or B; NN-B-601, style A or B; NN-B-621, style 2 or 4;

or Military Specification JAN-P-132. When fiberboard exterior

containers are used, such containers shall be fabricated from

fiberboard having a Mullen test of 275 pounds or more. Only

one type and style of container shall be used on any one

shipment.

7. 2. 4. 3. 2 For overseas shipment. --Commodity, prepared as

specified in 7. 2.4.1 and 7. 2.4. 2, shall be individually

secured by blocking, bracing, and cushioning in containers

constructed to fit the contents in a compact manner in

accordance with the requirements of Military Specification

JAN-P-103, style A or B; JAN-P-104; JAN- P-105, style A or

B; or JAN-P-106, style 2 or 4. Only one type and style of

container shall be used on any one shipment.

7. 2. 4.4 Marking. --In addition to any special marking required by the contract or order, shipments shall be marked

in accordance with Military Standard MIL-STD-129. The

nomenclature for refrigerators shall be as follows:

Refrigerators, Electric, Self-Contained, Domestic Type.

Type — (*) S3 ze --(*) Electrical Data —(*) — . Direction of Door Swing--(*).

Applicable data to be entered by the contractor.

7. 2. 4. 5 Identification of product. --Equipment, assemblies,

and parts shall be marked for identification In accordance

with Military Specification MIL-M-79H. The Identification

data applied to the Refrigerator shall be as follows:

Refrigerator, Electric, Domestic.

Type-- ( * ) , Size-— (*)--

Electrical Rating—(*)

Specification No. --()--

Stock No.

Mfr 5 s Part No. --(*) —

Serial No. —(*) —

Contract or Order No.

Mfr’s Name or Trade -mark- -

( *

)

U.S. Property

Applicable data to be entered by the contractor.

- 51

7.2. 4.6 Ordering Data - Procurement documents should

specify whether domestic or overseas shipment is required.

NAVY INTEREST: MC S Y

THE NATIONAL BUREAU OE STANDARDS

Functions and Activities

The functions of the National Bureau of Standards are set forth in the Act of Congress, March

3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and

maintenance of the national standards of measurement and the provision of means and methods

for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials,

devices, and structures; advisory services to Government Agencies on scientific and technical

problems; invention and development of devices to serve special needs of the Government; and the

development of standard practices, codes, and specifications. The work includes basic and applied

research, development, engineering, instrumentation, testing, evaluation, calibration services, and

various consultation and information services. A major portion of the Bureau’s work is performed

for other Government Agencies, particularly the Department of Defense and the Atomic Energy

Commission. The scope of activities is suggested by the listing of divisions and sections on the

inside of the front cover.

Reports and Publications

The results of the Bureau’s work take the form of either actual equipment and devices or published papers and reports. Reports are issued to the sponsoring agency of a particular project

or program. Published papers appear either in the Bureau’s own series of publications or in the

journals of professional and scientific societies. The Bureau itself publishes three monthly periodicals, available from the Government Printing Office: The Journal of Research, which presents

complete papers reporting technical investigations; the Technical News Bulletin, which presents

summary and preliminary reports on work in progress; and Basic Radio Propagation Predictions,

which provides data for determining the best frequencies to use for radio communications throughout

the world. There are also five series of nonperiodical publications: The Applied Mathematics

Series, Circulars, Handbooks, Building Materials and Structures Reports, and Miscellaneous

Publications.

Information on the Bureau’s publications can be found in NBS Circular 460, Publications of

the National Bureau of Standards ($1.25) and its Supplement ($0.75), available from the Superintendent of Documents, Government Printing Office. Inquiries regarding the Bureau’s reports and

publications should be addressed to the Office of Scientific Publications, National Bureau of

Standards, Washington 25, D. C.