UNITED STATES DEPARTMENT OF AGRICULTURE

Rural Utilities Service 

RUS BULLETIN 1728F-806 

RD-GD-2018-93

SUBJECT: Specifications and Drawings for Underground Electric Distribution

TO: RUS Electric Staff

RUS Electric Borrowers

DATES:

Effective Date: October 11, 2018 

Incorporation by Reference: IBR approved by Director, Office of the Federal Register - 2018. 

OFFICE OF PRIMARY INTEREST: Electric Staff Division

FILING INSTRUCTION: This bulletin replaces RUS Bulletin 1728F-806, Specifications and 

Drawing for Underground Electric Distribution, dated June 2000. 

PURPOSE: This bulletin contains complete specifications settings forth the RUS requirements for 

constructing rural underground electric distribution systems using state-of-the-art materials, equipment, 

and construction methods. This information is incorporated by reference in 7 CFR Part 1728. 

_______________________________________ _______________ 

Christopher A. McLean 

Assistant Administrator, Electric Program Date

Disclaimer: The contents of this guidance document does not have the force and effect of law and is not meant to

bind the public in any way. This document is intended only to provide clarity to the public regarding existing

requirements under the law or agency policies.
RUS Bulletin 1728F-806

 Page 2

TABLE OF CONTENTS

1 General 4

2 Storage of Material and Equipment 5

3 Handling of Cable 5

4 Plowing 6

5 Special Requirements for Coordination Between Owner and Contractor 7

Where Cable is to be Installed by Plowing

6 Trenching 7

7 Installing Cable in Trench 8

8 Installing Cable by Directional Bore 9

9 Minimum Bending Radius of Cable 9

10 Conduit 9

11 Tagging of Cables at Termination Points 10

12 Joints/Splices 10

13 Primary Cable Termination and Stress Cones 10

14 Special Precautions for Cable Joints/Splices and Terminations 11

15 Secondary and Service Connections 11

16 Pedestals 12

17 Inspection and Inventory of Buried Units 12

18 Backfilling 12

19 Equipment Pads 13

20 Transformers 13

21 Below Grade Enclosures 13

22 Utility Safety Signs 13

23 Sacrificial Anodes 14

24 Grounding 14

25 Cable Route Location Markers 14

26 Installed Cable and Acceptance Tests 14

27 Placement of Surge Arresters 15
RUS Bulletin 1728F-806

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Attachments 

Attachment A - Drawing Descriptions

Attachment B - Construction Drawings

Attachment C - RUS Standard Format and Meaning of Underground Distribution Assembly Numbers

INDEX:

ASSEMBLIES

Underground Distribution – Bul. 1728F-806

SPECIFICATIONS AND STANDARDS:

Construction Specifications and Drawings – Bul. 1728F-806

Underground Distribution – Bul. 1728F-806

UNDERGROUND DISTRIBUTION:

Underground Rural Distribution – Bul. 1728F-806

ABBREVIATIONS

ANSI – American National Standards Institute 

IEEE - Institute of Electrical and Electronic Engineers, Inc.

NEMA - National Electrical Manufacturers Association 

NESC - Compliance with National Electrical Safety Code

NRECA – National Rural Electric Cooperative Association
RUS Bulletin 1728F-806

 Page 4

1 GENERAL

a These specifications provide for the construction of underground distribution power 

facilities as specified by the owner. The owner is defined as the organization contracting 

for the services and when used in connection with RUS financed facilities, is 

synonymous with the term borrower as defined in ~1710.2.

b It is the responsibility of the owner to ensure that all construction work shall be 

accomplished in a thorough and workmanship manner in accordance with the staking 

sheets, plans and specifications, and the construction drawings.

c If construction work is performed by the Owner's force labor account crews instead of a 

contractor, any reference to "Contractor" in the narrative portions or drawings of this 

bulletin shall also apply to the force labor account crews.

d The provisions of 7 CFR 1724.50, Compliance with National Electrical Safety Code 

(NESC) applies to all borrower electric system facilities regardless of the source of 

financing. 

(1) The owner shall ensure that its electric system, including all electric distribution,

transmission, and generating facilities, is designed, constructed, operated, and 

maintained in accordance with all applicable provisions of the most current and 

accepted criteria of the NESC and all applicable and current electrical and safety 

requirements of any State or local government entity in which they serve. Copies 

of the NESC may be obtained from the Institute of Electrical and Electronic 

Engineers, Inc.,

EEE Customer Service

 445 Hoes Lane

 P.O. Box 1331

 Piscataway, NJ 08855-1331

 Telephone: (800)678-4333

 Web site: http://shop.ieee.org/ieeestore/

(2) This requirement applies to the borrower’s electric system regardless of the

source of financing.

(3) Any electrical standard requirement established by RUS are in addition to, and

not in substitution for or a modification of, the most current and accepted criteria 

of the NESC and any applicable electrical or safety requirement of any State or 

local governmental entity.
RUS Bulletin 1728F-806

 Page 5

e Overhead distribution design specifications and standards are in RUS Bulletin 1728F-804

and Bulletin 1728F-803. With the underground assemblies attached to the overhead 

facilities, please note: Overhead distribution circuits shall be constructed with not less 

than the Grade C strength requirements as described in Section 26, Strength 

Requirements, of the NESC when subjected to the loads specified in NESC Section 25, 

Loadings for Grades B and C. Overhead transmission circuits shall be constructed with 

not less than the Grade B strength requirement as described in NESC Section 26.

f An effective program for identifying underground cable routes is a good mapping system.

g The drawings of equipment and materials shown in the construction assemblies depict the 

general categories of items found in RUS Informational Publication 202-1, “List of 

Materials Acceptable for Use on System of RUS Electrification Borrowers” (“List of 

Material”). Any drawing of any piece of equipment or material that resembles a specific 

product of a manufacturer is unintentional.

h Owners shall use the new assembly and guide coding system on the new assembly units 

and guide drawings as listed in the RUS Bulletin 1728F-806. However, owners may 

elect to continue using the old numbers of these assembly and guide drawings, but only 

for the previous (dated June 2000 publication) assemblies and guide drawings and their 

old numbers if they make the applicable material changes to the old assemblies.

2 STORAGE OF MATERIAL AND EQUIPMENT

All material and equipment to be used in construction shall be stored so as to be protected from 

deteriorating effects of the elements. If outdoor storage cannot be avoided, the material and 

equipment must be protected from the elements as appropriate, and with due regard to public 

safety.

3 HANDLING OF CABLE

The cable shall be handled carefully at all times to avoid damage, and shall not be dragged across 

the ground, fences or sharp projections. This includes setting up utility signs to mark cable laying 

in a vehicle traffic area to prevent cable damage. Care shall be exercised to avoid excessive 

bending of the cable. The ends of the cable shall be sealed at all times against moisture with 

suitable end caps. Where it is necessary to cut the cable, the ends will be terminated or sealed 

immediately after the cutting operation.
RUS Bulletin 1728F-806

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4 PLOWING

a When cables, flexible conduit, and cable-in-conduit are to be installed by plowing, it is 

the responsibility of the owner to ensure that the plowing equipment be subject to the 

approval of the Owner and the public authorities having jurisdiction over highway and 

road rights-of-way. The plow shall be provided with a means to assure positive holddown of the plow blade to provide proper depth at all times.

b The design of the plowshare shall ensure that the cable passing through the plow will not 

be bent in a radius less than 12 times the outside diameter of the cable. The equipment 

shall be capable of extending the plow a minimum of 6 inches below the specified depth 

under all terrain conditions of plow utilization.

c The owner shall ensure that equipment and construction methods used during 

construction cause minimum displacement of the soil. The slot made in the soil by the 

cable plows shall be closed immediately by driving a vehicle track or wheel over the slot 

or by other suitable means.

d Starting and terminating points of the plowing operation shall be excavated prior to cable 

installation to reduce possible cable damage and to assure sufficient burial depth.

e During the plowing operation, care is to be exercised to feed the cable or wire into the 

ground through the plow loosely and at minimum tension. Besides using proper 

equipment and construction methods, supervision by the owner or owner’s representative 

shall be furnished at all times at the site of plowing operations to assure compliance with 

these specifications.

f If, during the plowing operation, the plow should strike a buried object or rock that would 

stop the equipment and necessitate removal of the plow from the ground, the plow must

be removed from the ground carefully and, if practical, without backing the plow. If it 

should be necessary to back the plow to remove it from the ground, the cable must be 

uncovered a sufficient distance back for inspection by the Owner to determine whether 

the cable or wire has been damaged.

g The cable shall be inspected carefully as it is payed out from the reel to be certain that it 

is free from visible defects. Every instance of damaged cable observed at any time, 

whether prior to installation, during installation, or when discovered by test or 

observation subsequent to installation in plant, shall be immediately called to the 

attention of the Owner. Repair or correction of such damage shall be done promptly and 

in accordance with the written instruction of the Owner. The location of any such repair 

shall be indicated on the staking sheet.
RUS Bulletin 1728F-806

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5 SPECIAL REQUIREMENTS FOR COORDINATION BETWEEN OWNER AND

 CONTRACTOR WHERE CABLE IS TO BE INSTALLED BY PLOWING

a Staking sheets shall be reviewed jointly in the field by the contractor and Owner prior to 

the start of construction. At that time, the Contractor shall propose any desirable changes 

or clarifications. These changes, if approved by the Owner, shall be made and recorded 

on the staking sheets. No changes on the staking sheets shall be made by the Contractor 

without the prior written approval of the Owner. A representative of the Owner shall 

remain in the immediate vicinity of the plowing operations at all times and will consider 

and possibly approve any acceptable changes proposed by the Contractor. A 

representative of the Owner shall also inspect any damage to cable and approve 

acceptable methods of repair or correction of such damage in accordance with the 

provisions of these specifications.

b In the event that rock is encountered during the plowing operation so that the buried cable 

cannot be installed to the required minimum depths in soil, the Contractor shall determine 

for the Owner the nature and extent of the rock encountered. Based on this information, 

the Owner will determine whether the cable is to be rerouted, trenched in rock, protected 

by conduit or concrete or a change made to aerial construction. This decision shall be 

made promptly, and appropriate changes in units shall be made on the staking sheets. 

Such changes shall be in writing, dated, and initialed by the Owner.

c Due to the necessity of making on-the-spot corrections and changes on staking sheets, it 

may not be possible for the Owner to issue revised staking sheets to the Contractor in all 

cases. When changes are made, dated, and initialed by the Owner on a set of the 

Contractor's staking sheets, it shall be the Contractor's responsibility to transfer these 

changes to all other sets of staking sheets being used by the Contractor for construction 

purposes.

d The Contractor shall provide a competent representative to work with the Owner on the 

inventory and inspection of buried cable units. The inventory of buried cable will be 

made as soon after the plowing operation as practical to avoid later disagreements on the 

quantity of cable installed when changes are required in the project.

6 TRENCHING

a It is the responsibility of the owner to ensure that all trenching depths specified are listed 

as minimum as measured from the final grade to the top surface of the cable or conduit. 

The routing shall be as shown on the staking sheets and plans and specifications unless

conditions encountered are such that changes are necessary to accomplish the work. In 
RUS Bulletin 1728F-806

 Page 8

such event, the Owner shall be notified promptly. If rock or other difficult digging (i.e. 

trench caves in) is involved, the Contractor shall determine the nature and extent of the 

difficulty, and the Owner will determine whether rerouting, rock trenching, plowing, rock 

sawing or other changes are necessary. Loose soil or crumbly rock shall not be 

considered as "difficult digging." The trench widths specified are minimums and should 

be increased as necessary to obtain the required depths in loose soils.

b Where trenches are intended for more than one cable, particular care shall be taken to 

provide for extra depth and width to allow for soil falling into the trench during the laying 

of the first cables.

c Care shall be exercised to minimize the likelihood of waterflow since this may cause 

trench damage and reduction in trench depth. If this occurs, the trench must be cleared to 

the specified depth before installing the cable.

d All trenches including secondary and service trenches shall follow straight lines between 

staked points to the greatest extent possible to help in cable locating. The trenches shall 

be dug so that the bottom has a smooth grade. Large rocks, stones and gravel in excess of 

l inch shall be removed from the bottom of the trench. Where this cannot be done, a 2 

inch bed of sand or clean soil shall be placed in the bottom of the trench.

e Construction shall be arranged so that trenches will be left open for the shortest practical 

time to avoid creating a hazard to the public and to minimize the likelihood of collapse of 

the trench due to other construction activity, rain, accumulation of water in the trench, 

etc.

7 INSTALLING CABLE IN TRENCH

a It is the responsibility of the owner to ensure that the cable shall be placed in the trench as 

soon after the trenching operation as feasible. Wherever possible, cable shall be payed 

out from the reel mounted on a moving vehicle or trailer. The reel shall be supported so 

that it can turn easily without undue strain on the cable. The cable shall be carefully 

placed in the trench by hand. All cable placements shall be done under constant 

supervision to be certain that no damage to the cable occurs.

b The cable shall be inspected carefully as it is removed from the reel in laying operations 

to be certain that it is free from visible defects. The Owner shall decide upon corrective 

action when defects are discovered.

c Where more than one cable are to be placed in a trench, the spacings required by the 

specifications must be observed. Care shall be taken that any soil falling into the trench 
RUS Bulletin 1728F-806

 Page 9

during the laying of the first cable does not reduce the clearances of the last cable below 

that specified. Should this occur, the excess soil shall be removed carefully by hand or 

with equipment so as not to damage the installed cables.

d Sufficient slack, and in no case less than 24 inches, shall be left at all risers, transformer 

pads, pedestals and terminal points so that movements of cable after backfilling will not 

cause damaging strain on the cable or terminals. The cable trench shall be mechanically 

compacted 36 inches minimum from all riser poles, pads, pedestals and terminal points.

e The ends of all secondary cable terminated below ground shall be long enough to reach 

at least 12 inches above the top of the underground enclosure.

8 INSTALLING CABLE BY DIRECTIONAL BORE

It is the responsibility of the owner to investigate the boring route. If the bore is in public/private rightof-way, a review of the permit is required to determine what type of construction may be required for 

the installation. During the boring operation, multiple bend/turns should be avoided as it increases the 

pulling tension on the cable. The cable and or conduits must be handled and or trained with proper 

guides at the entry and exit points to prevent damage. Procedures for cable handling in trenching and 

plowing also apply to installation by directional boring.

9 MINIMUM BENDING RADIUS OF CABLE

The minimum bending radius of primary cable is 12 times the overall diameter of the cable. The 

minimum bending radius of secondary and service cable is six times the overall diameter of the cable. 

In all cases the minimum radius specified is measured to the surface of the cable on the inside of the 

bend. No cable bends shall be made within 6 inches of a cable terminal base.

10 CONDUIT

a Cable Protection shall have all exposed ends of the conduit plugged during construction 

to prevent the entrance of foreign matter and moisture into the conduit. Burrs or sharp 

projections which might injure the cable shall be removed. Conduits shall be sized to 

meet the fill limits based on the number and size of cables to be installed. Lubricants used 

in the aid of cable pulling shall be compatible with both the conduit and cable.
RUS Bulletin 1728F-806

 Page 10

b Direct Buried Riser shield or conduit shall extend at least 18 inches below grade at all 

riser poles. If full round conduit is used as a riser shield, an end bell shall be installed on 

the lower end to prevent damage to the cable. Any aluminum portion of the riser shall not 

be placed below grade.

c Three Phase Riser Guide conduit provides good protection when all three phases are in 

one conduit. The advantage of each phase in a separate conduit is having improved 

reliability and lower cable pulling tensions. However, the disadvantages has the separated

phase and neutral currents causing induced current in magnetic metal conduits leading to 

increases in line losses which develops heat that can damage the cable insulation. 

D It is the responsibility of the owner to perform cable pulling calculations prior to pulling 

through a conduit system so that maximum cable tensions are not exceeded. When 

pulling conductors into a conduit system, the owners shall lubricate cable as needed to 

reduce pulling tensions.

11 TAGGING OF CABLES AT TERMINATION POINTS

As the cables are laid, it is the responsibility of the owner to ensure that they are identified and tagged. 

The identification shall be of a permanent type, such as that done on plastic or corrosion resistant metal 

tags. The tag shall be securely attached to the cable. Paper or cloth tags are not acceptable.

12 JOINTS/SPLICES

a Cable joints/splices shall be of the pre-molded rubber, heat-shrink, or cold-shrink type, of 

the correct voltage rating and shall be installed in accordance with the joint/splice 

manufacturer's instructions. Joints/Splices that depend solely on tape for a moisture 

barrier shall not be used.

b Not more than one joint/splice may be permitted for each 2000 feet of cable installed 

unless authorized by the Owner. No bends may be permitted within 12 inches of the ends 

of a joint/splice. The cable or circuit numbers and the exact location of all joints/splices 

shall be noted on the staking sheets (as built).

13 PRIMARY CABLE TERMINATION AND STRESS CONES

a Prefabricated stress cones or terminations shall be installed in accordance with the 

manufacturer's instructions at all primary cable terminals. They shall be suitable for the 

size and type of cable that they are used with and for the environment in which they will 
RUS Bulletin 1728F-806

 Page 11

operate. Any indication of misfit, such as a loose or exceptionally tight fit, shall be called 

to the Owner's attention. The outer semi-conductive surface of the termination shall be 

bonded to the system neutral. A heat-shrink or cold-shrink sleeve shall be installed to 

seal between the body of the termination and the cable jacket.

14 SPECIAL PRECAUTION FOR CABLE JOINTS/SPLICES AND TERMINATIONS 

A portable covering or shelter shall be available for use when joints/splices or terminations are being 

prepared and when prefabricated terminations are being switched. The shelter shall be used as necessary 

to keep rain, snow and windblown dust off the insulating surfaces of these devices. Since cleanliness is 

essential in the preparation and installation of primary cable fittings, care shall be exercised to prevent 

the transfer of conducting particles from the hands to insulating surfaces. Mating surfaces shall be 

wiped with a solvent to remove any possible accumulation of dirt, moisture or other conducting 

materials. A silicone grease or similar lubricant should be applied afterwards in accordance with the 

manufacturer's recommendations. Whenever prefabricated cable devices are opened, the unenergized 

mating surfaces shall be lubricated with silicone grease before the fittings are reconnected.

15 SECONDARY AND SERVICE CONNECTIONS

a 15.1 A suitable inhibiting compound shall be used with all secondary and service

connections.

b All secondary cable connections located below grade or in secondary pedestals shall be 

made with pre-insulated secondary connector blocks. Diving bells with open terminals, 

insulating boots or moisture barriers that depend solely on tape are not acceptable.

c All transformer secondary phase terminal connections shall be completely insulated. If 

the secondary phase terminals are threaded studs, the connection shall be made with a 

pre-insulated secondary transformer connection block. If the transformer secondary 

phase terminals are insulated cable leads, connection shall be made with a pre-insulated 

secondary connector block or with a secondary prefabricated joint/splice when the 

transformer leads continue directly to the service.

d If a transformer is so large that it must have secondary spades, the spades shall be taped 

or otherwise insulated. Boots used for insulation shall be taped or secured so that they 

cannot be readily slipped off.

e Secondary connections to terminals of pole-mounted transformers shall be made so that 

moisture cannot get inside the cable insulation. This may be accomplished by covering 

the terminals and bare conductor ends with an appropriate moisture sealant (a listing of 
RUS Bulletin 1728F-806

 Page 12

acceptable items is in RUS Informational Publication 202-1, List of Materials for use on 

systems of RUS Electrification Borrowers) or by providing a drip loop.

f 15.6 The secondary connections and insulation shall have accommodations for all future 

and existing services as shown on the plans and specifications.

16 PEDESTALS

Where required, pedestal stakes shall be driven vertically into the bottom of the trench before cables are 

placed, and shall be located as shown on the staking sheets. Pedestal posts and supporting stakes shall 

be in place before the cable is installed. All pedestals should be approximately at the same height above 

finished grade.

17 INSPECTION AND INVENTORY OF BURIED UNITS 

Before any backfilling operations are begun, it is the responsibility of the owner to ensure that the

Contractor and Owner shall jointly inspect all trenches, cable placement, risers, pedestal stakes, and 

other construction that will not be accessible after backfilling, and an inventory of units shall be taken. 

If corrections are required, a second inspection shall be made after completion of the changes.

18 BACKFILLING

a The first 6 inches of trench backfill shall be free from rock, gravel or other material 

which might damage the cable jacket. In lieu of cleaning the trench, the Contractor may, 

at the Contractor's option, place a 2 inch bed of clean sand or soil under the cable and 4 

inches of clean soil above the cable. Cleaned soil backfill when used shall contain no 

solid material larger than l inch. This soil layer shall be carefully compacted so that the 

cable will not be damaged.

b Backfilling shall be completed in such a manner that voids will be minimized. Excess 

soil shall be piled on top and shall be well tamped. 

c 18.3 Pieces of scrap cable or other material remaining after installation shall not be 

buried in the trench as a means of disposal.

c Conduit provides protection for the cable to be installed. However, the backfilling 

method for cable in conduit shall be the same as direct buried cable. Additional 

protection can be obtained by pouring a concrete cap over a partial filled backfill above 

the direct buried cable or conduit.
RUS Bulletin 1728F-806

 Page 13

Further protection for the conduits is done by concrete encapsulation using spacers to 

insure enough concrete surrounds the conduits.

19 EQUIPMENT PADS

The site for the pad shall be on undisturbed earth adjacent to but not over the trench. The site shall be 

cleared of all debris and excavated to the specified depth. Gravel or sand may be added to the site and 

thoroughly compacted. The developer/property owner shall provide the finished grade so steps can be 

taken to insure foundations are installed level at the specified elevation.

20 TRANSFORMERS

Transformers shall be handled carefully to avoid damage to the finish and shall be positioned in 

accordance with the staking sheets and the plans and specifications. Only qualified and experienced 

personnel shall be allowed to make connections and cable terminations.

21 BELOW GRADE ENCLOSURES

Excavations for sleeve-type transformer pads and other below-grade enclosures shall be made so as to 

disturb the surrounding earth as little as practical. Enclosures shall be installed with side walls plumb. 

When enclosures are of fiber, plastic, or other semi-flexible material, backfilling should be done with 

covers in place and with careful tamping so as to avoid distortion of the enclosure. When installation is 

complete, the cover of the enclosure shall not be lower than and not more than 2 inches higher than the 

grade specified by the Owner. Soil in the immediate vicinity shall be tamped and sloped away from the 

enclosure. At the Owner's option, the excess soil shall be removed from the site or spread evenly over 

the surface of the ground to the satisfaction of the Owner.

22 UTILITY SAFETY SIGNS

a Utility safety signs shall be in accordance with the provisions of ANSI Z535.2011 and 

any updated revision of these codes when it is released, Environmental and Facility 

Safety Signs shall be applied in accordance with RUS drawings. Copies of the ANSI 

Z535.2-2011 may be obtained from:

National Electrical Manufacturers Association (NEMA)

1300 North 17th Street

Suite 1847

Rosslyn, Virginia 22209.
RUS Bulletin 1728F-806

 Page 14

b Transformers and other high voltage equipment enclosures installed at ground level in a 

public access area shall display owner/operator contact information with contact name 

and telephone number. 

23 SACRIFICIAL ANODES

Sacrificial anodes specified shall be installed with backfill package intact and connecting leads 

positioned for proper connection after the equipment is in place. Anodes shall not be moved, positioned, 

lifted, nor lowered into place by pulling on the connecting leads.

24 GROUNDING

a 24.1 All neutral conductors, ground electrodes, sacrificial anodes and grounded parts of 

equipment shall be interconnected. All interconnections for grounding shall be made and 

consistent with installation standard used by the owner. A copper-clad or galvanized 

steel ground rod with minimum length of 8 feet shall be installed at all equipment 

locations and at all accessible cable joints/splices and taps.

b 24.2 All pad-mounted equipment enclosures, including transformers, shall be grounded in 

such a manner that two separate grounding paths exist between the enclosure and the 

grounding rod(s).

c 24.3 Counterpoise grounding is an effective means of reducing the impedance to ground 

in areas of high-resistivity soils. A common designed counterpoise is a horizontal grid or 

conductor below ground level functioning as one plate of a large capacitor, with the 

conductive layers of the earth acting as the other plate. A counterpoise shall not be used 

when normal electrode grounding can be installed.

25 CABLE ROUTE LOCATION MARKERS

The above ground location of permanent cable markers shall be as shown on the staking sheets. URD 

cable markers provide identification of cable routes to contractors, other utilities, and general public to 

guard against unauthorized contact. 

26 INSTALLED CABLE AND ACCEPTANCE TESTS 

a The best method for quality assurance of the cable is to require the manufacturer to 

submit samples for testing before the cable is accepted. The acceptance tests are simple 
RUS Bulletin 1728F-806

Page 15

checks to ensure that the cable components meet the current specifications and 

compliance standards. NRECA has a list of cable testing facilities. The typical cable 

sampling rates are to test one sample, each, from the first and last reel on the order of 

50,000 feet or less and one sample for each additional 50,000 feet of cable ordered. 

b Continuity: After installation of the cable, authorized personnel shall perform a simple 

continuity test on the system. This can easily be accomplished by grounding the 

conductor at the source and checking for continuity from the end of each tap with an 

ohmmeter or with a battery and ammeter.

c WARNING: A hazardous voltage may exist on the cable; therefore, before handling the 

cable, the conductor shall be grounded to permit any charge to drain to earth.

27 PLACEMENT OF SURGE ARRESTERS

The arrester connection on a riser pole shall have the grounding conductor going from system neutral to

the pole ground to surge arrester ground than to cable neutral/ground. The combination of both the line 

lead length and ground lead length shall be less than 3 feet.27.2 The higher margin of protection on the 

underground cable system is reached when the riser type class arresters are used at each overhead riser 

pole cable termination. Also, by the placement of a distribution class arresters at open points on the 

cable system to help limit the transient voltage reflection peaks. Note a higher surge arrester MCOV 

rating should be selected for both open and mid-point arresters on the underground cables system as 

compared to the MCOV rating of the overhead riser pole arrester.

Bulletin 1728F-806

Attachment A - Drawing Descriptions

Attachment B - Construction Drawings

Attachment C - RUS Standard Format and Meaning of Underground Distribution Assembly Numbers
RUS Bulletin 1728F-806

 Attachment A

Page 1

 Attachment A 

SECTION CATEGORY DESCRIPTIONS

UA SINGLE-PHASE RISER POLE ASSEMBLY UNITS

Single-Phase Riser Primary Pole Installations

UA1 Single Phase Cable Terminal Pole with Two Brackets

UA2 Single Phase Cable Terminal Pole with One Bracket

UA3 Single Phase Cable Terminal Pole with Crossarm Mounted Cutout

UA4 Single Phase Cable Terminal Pole without Cutout

UA.G Cable Terminal Pole Arrester Connection Guide

UA1.USG Alternate Connection For Underground Source Guide

UB TWO-PHASE RISER POLE ASSEMBLY UNITS

Two-Phase Riser Primary Pole Installations

UB1 Two Phase Cable Terminal Pole with Cutouts and Crossarm Mounting Arresters

UB2 Two Phase Cable Terminal Pole with Cutouts and Bracket Mounting Arresters

UB3 Two Phase Cable Terminal Pole without Cutouts and Crossarm Mounting 

Arresters

UB4 Two Phase Cable Terminal Pole without Cutouts and Bracket Mounting Arresters

UB5 Two Phase Cable Terminal Pole with Upper Crossarm Mounting Cutouts and 

Crossarm Mounting Arresters

UB6 Two Phase Cable Terminal Pole with Upper Crossarm Mounting Cutouts and 

Bracket Mounting Arresters

UC THREE-PHASE RISER POLE ASSEMBLY UNITS

Three-Phase Riser Primary Pole Installations

UC1 Three Phase Cable Terminal Pole with Cutouts and Crossarm Mounting Arresters

UC2 Three Phase Cable Terminal Pole with Cutouts and Bracket Mounting Arresters

UC3 Three Phase Cable Terminal Pole without Cutouts and Crossarm Mounting 

Arresters

UC4 Three Phase Cable Terminal Pole without Cutouts and Bracket Mounting 

Arresters

UC5 Three Phase Cable Terminal Pole with Upper Crossarm Mounting Cutouts and 

Crossarm Mounting Arresters
RUS Bulletin 1728F-806

 Attachment A

Page 2

UC6 Three Phase Cable Terminal Pole with Upper Crossarm Mounting Cutouts and 

Bracket Mounting Arresters

UC7.1 Bracket Mounting Switches

UC7.2 Horizontal Mounting Switches

UC7.3 Vertical Switches Mounted on Three Crossarms

UC7.4 Vertical Switches Mounted on Four Crossarms

UC8.1 Three Phase Cable Terminal Pole with Vertical Framing and Two Brackets per 

Phase

UC8.2 Three Phase Cable Terminal Pole with Vertical Framing and One Brackets per 

Phase

UF FOUNDATIONS ASSEMBLY UNITS

Types & Products Used in Foundation Installations

UF.PBC, Primary Pull Box Underground Cable

UF.PBN

UF1.BC, Single Phase Equipment Foundations

UF1.BN

UF1.PC, Single Phase and Three Phase Equipment Foundations

UF1.PN,

UF3.PN

UF3.BC, Three Phase Equipment Foundations

UF3.BN,

UF3.VC

UF3.PC Concrete Pad for Thee Phase Equipment

UG TRANSFORMER ASSEMBLY UNITS

Types & Products Used in Transformer Installations

UG1.01, Single Phase One Bushing Padmounted Transformer (Radial Feed)

UG1.1

UG1.2 Single Phase Two Bushing Padmounted Transformer (Radial Feed)

UG1.02, Single Phase Two Bushing Padmounted Transformer (Loop Feed)

UG1.3

UG2.1 Open Delta Connection with Single Phase Padmounted Transformers

UG3.01, Three Phase Three Bushing Padmounted Transformer (Radial Feed)

UG3.1

UG3.2 Three Phase Six Bushing Padmounted Transformer (Radial Feed)

UG3.02, Three Phase Six Bushing Padmounted Transformer (Loop Feed)

UG3.3
RUS Bulletin 1728F-806

 Attachment A

Page 3

UH GROUNDING ASSEMBLY UNITS

Types & Methods used in Grounding Installations

UH.01 Ground Rod Assembly

UH1.1 Grounding Assembly for Padmounted Transformers and Enclosures (1 Rod)

UH1.2 Grounding Assembly for Padmounted Transformers and Enclosures (2 Rod)

UH1.4 Grounding Assembly for Padmounted Transformers and Enclosures (4 Rod)

UH1.7 Grounding Array for Padmounted Transformers and Enclosures

UH2.0, Counterpoise Grounding

UH2.2

UH2.7 Trench Type Grounding Assembly – Riser to Transformer Outside of Conduit

UH3.1 Grounding Assembly for Sectionalizing Enclosures (1 Rod)

UH4.1 Grounding Assembly for Cable Above Grade Enclosures (1 Rod)

UH4.1G Jacketed Cable Grounding Installation (Heat Shrink or Cold Shrink)

UJ SECONDARY ASSEMBLY UNITS

Types & Products used in Secondary Installations

UJ1.01 Secondary Splice

UJ1 Secondary Insulated Connector Block

UJ2 Transformer Connector Block

UJ3.1 Secondary Pedestal Single Phase Above Grade Enclosure

UJ3.3 Secondary Pedestal Three Phase Above Grade Enclosure

UJ4.1 Secondary Handhole Single Phase Below Grade Enclosure

UJ4.3 Secondary Handhole Three Phase Below Grade Enclosure

UK SECONDARY SERVICE ASSEMBLY UNITS

Types & Products used in Secondary Meter Installations

UK1.1 Secondary Cable Riser Pole without Meter Base

UK2.1 Secondary Riser Bottom Connection

UK2.2 Secondary Riser Bottom Side Connection

UK3.1 Temporary Conduit Termination without Meter Base

UK4 Secondary Breaker

UM MISCELLANEOUS ASSEMBLY UNITS

Miscellaneous Installation Products & Service

UM1.XX Right-Of-Way Clearing

UM2 Cable Route Marker

UM3 Safety Signs
RUS Bulletin 1728F-806

 Attachment A

Page 4

UM6.C, Caps and Plugs

UM6.PL

UM6.EL Elbows

UM6.FI Fault Indicators

UM6.IN Inserts

UM6.JN Multipoint Junctions

UM6.PK Parking Stands

UM6.RK, Primary Terminations

UM6.SP,

UM6.T,

UM6.TS

UO OUTDOOR LIGHTING ASSEMBLY UNITS

Types & Products used in Outdoor Lighting Installations

UO1 Outdoor Light Installation Guide

UO2 Light Structure Installation Guide

UP SYSTEM PROTECTION ASSEMBLY UNITS

System Cable Protection & Interface Products Used

UP1, Arresters

UP2,

UP3

UP4, Arresters and Anodes

UP5

UP7.01, Riser Shield, Back Plate, Conduit Cable Riser

UP7.02,

UP7.03

UP7.04 Conduit Elbow

UP7.B1 Single Conduit Riser with Stand-Off Brackets

UP7.B2 Two Conduit Riser with Stand-Off Brackets

UP7.B3 Three Conduit Riser with Stand-Off Brackets

UP7.C Strap Attached Conduit Riser

UP7.FC Flex Conduit Riser

UP7.UG U-Guard Riser

UP8 Underground Conduit

UQ METERING ASSEMBLY UNITS

Types & Products used in Metering Installations
RUS Bulletin 1728F-806

 Attachment A

Page 5

UQG Meter Options Guide

UQ_._B_ Meter on Building

UQ_._P_, Through Type Meter Pedestal and Meter Pedestal Wood Post

UQ_._S_

UQ_._T_ Meter Pedestal at Transformer

UR RECLOSER ASSEMBLY UNITS

Types & Products used in Recloser Installations

UR3._ _ Three Phase Padmounted Recloser

US SECTIONALIZING ASSEMBLY UNITS

Types & Products used in System Sectionalizing Installations

US1.DC Single Phase Padmounted Transformer Deferred Unit Cabinet Type

US1.DP Single Phase Padmounted Transformer Deferred Unit Pedestal Type

US1.DV Single Phase Padmounted Transformer Deferred Unit Pad Sleeve Type

US1.PJ., Single and Three Phase Primary Junctions

US3.PJ.

US_SF_ Switch / Fuse Enclosure Installation

US1.SF_, Single Pole Switching 200 Amp Fuse Enclosure Installation Wiring Diagrams 

US2.SF_ (Single Phase & Two Phase)

US3.SF_ Fuse Enclosure (200-600 Amp) Wiring Diagrams (Three Phase)

UT TRENCH ASSEMBLY UNITS

Types & Products used in Trenching & Boring Installations

UT1, Trenches for Conduit and Direct Burial Cables

UT2,

UT3,

UT4,

UT5

UY VOLTAGE ASSEMBLY UNITS

Types & Products used in Voltage Control Installations

UY1.1.XX Single Phase Padmounted Voltage Regulation with No Bypass Switch

UY1.1.XXSWSingle Phase Padmounted Voltage Regulation with Bypass Switch

UY3.2L Three Phase Padmounted Shunt Reactor with Loop Feed

UY3.3L Three Phase Padmounted Capacitor with Loop Feed
RUS Bulletin 1728F-806

 Attachment B

Page 1

Attachment B

Construction Drawings
INDEX UA

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UA1 UA1 SINGLE PHASE CABLE TERMINAL POLE WITH TWO BRACKETS

UA2 UA2 SINGLE PHASE CABLE TERMINAL POLE WITH ONE BRACKET

UA3 UA3 SINGLE PHASE CABLE TERMINAL POLE WITH CROSSARM 

MOUNTED CUTOUT

UA4 SINGLE PHASE CABLE TERMINAL POLE WITHOUT CUTOUT

UA.G UX11 CABLE TERMINAL POLE ARRESTER CONNECTION GUIDE

UA1.USG UNDERGROUND SOURCE CONNECTION GUIDE

SINGLE PHASE RISER POLE ASSEMBLY UNITS






INDEX UB

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UB1 (UB1) TWO PHASE CABLE TERMINAL POLE WITH CUTOUTS AND 

CROSSARM MOUNTING ARRESTERS

UB2 (UB2) TWO PHASE CABLE TERMINAL POLE WITH CUTOUTS AND 

BRACKET MOUNTING ARRESTERS

UB3 (UB3) TWO PHASE CABLE TERMINAL POLE WITHOUT CUTOUTS AND 

CROSSARM MOUNTING ARRESTERS

UB4 (UB4) TWO PHASE CABLE TERMINAL POLE WITHOUT CUTOUTS AND 

BRACKET MOUNTING ARRESTERS

UB5 TWO PHASE CABLE TERMINAL POLE WITH UPPER CROSSARM 

MOUNTING CUTOUTS AND CROSSARM MOUNTING ARRESTERS

UB6 TWO PHASE CABLE TERMINAL POLE WITH UPPER CROSSARM 

MOUNTING CUTOUTS AND BRACKET MOUNTING ARRESTERS

TWO PHASE RISER POLE ASSEMBLY UNITS






INDEX UC

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UC1 (UC1) THREE PHASE CABLE TERMINAL POLE WITH CUTOUTS AND

CROSSARM MOUNTING ARRESTERS

UC2 (UC2) THREE PHASE CABLE TERMINAL POLE WITH CUTOUTS AND

BRACKETS MOUNTING ARRESTERS

UC3 THREE PHASE CABLE TERMINAL POLE WITHOUT CUTOUTS AND

CROSSARM MOUNTING ARRESTERS

UC4 THREE PHASE CABLE TERMINAL POLE WITHOUT CUTOUTS AND

BRACKET MOUNTING ARRESTERS

UC5 THREE PHASE CABLE TERMINAL POLE WITH UPPER CROSSARM 

MOUNTING CUTOUTS AND CROSSARM MOUNTING ARRESTERS

UC6 (UC2-1) THREE PHASE CABLE TERMINAL POLE WITH UPPER CROSSARM 

(UC2-2) MOUNTING CUTOUTS AND BRACKET MOUNTING ARRESTERS

UC7.1 BRACKET MOUNTED SWITCHES

UC7.2 (UC5-1,UC6-1) HORIZONTAL MOUNTED SWITCHES

UC7.3 VERTICAL SWITCHES MOUNTED ON THREE CROSSARMS

UC7.4 VERTICAL SWITCHES MOUNTED ON FOUR CROSSARMS

UC8.1 THREE PHASE CABLE TERMINAL POLE WITH VERTICAL FRAMING

AND TWO BRACKETS PER PHASE

UC8.2 THREE PHASE CABLE TERMINAL POLE WITH VERTICAL FRAMING

AND ONE BRACKET PER PHASE

THREE PHASE RISER POLE ASSEMBLY UNITS












INDEX UF

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

PRIMARY PULL BOX UNDERGROUND CABLE

UF.PBC CONRETE PRIMARY PULL BOX

UF.PBN NON-CONRETE PRIMARY PULL BOX

SINGLE PHASE EQUIPMENT FOUNDATIONS

UF1.BC (UM1-7C) CONRETE BOX PAD FOR SINGLE PHASE EQUIPMENT

UF1.BN (UM1-7NC) NON-CONCRETE BOX PAD FOR SINGLE PHASE EQUIPMENT

SINGLE PHASE AND THREE PHASE EQUIPMENT FOUNDATIONS

UF1.PC (UM1-5C) CONCRETE PAD FOR SINGLE PHASE EQUIPMENT

UF1.PN (UM1-5NC) NON-CONCRETE PAD FOR SINGLE PHASE EQUIPMENT

UF3.PN NON-CONCRETE PAD FOR THREE PHASE EQUIPMENT

THREE PHASE EQUIPMENT FOUNDATIONS

UF3.BC CONCRETE BOX PAD FOR THREE PHASE EQUIPMENT

UF3.BN NON-CONCRETE BOX PAD FOR THREE PHASE EQUIPMENT

UF3.VC CONCRETE VAULT FOR THREE PHASE EQUIPMENT

UF3.PC (UM1-6C) CONCRETE PAD FOR THREE PHASE EQUIPMENT

FOUNDATION ASSEMBLY UNITS





INDEX UG

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

SINGLE PHASE ONE BUSHING PADMOUNTED TRANSFORMER

(RADIAL FEED)

UG1.01 SINGLE PHASE ONE BUSHING PADMOUNTED TRANSFORMER ONLY

UG1.1 (UG6) RADIAL TYPE SINGLE PHASE ONE BUSHING PADMOUNTED

TRANSFORMER

UG1.2 SINGLE PHASE TWO BUSHING PADMOUNTED TRANSFORMER

(RADIAL FEED)

SINGLE PHASE TWO BUSHING PADMOUNTED TRANSFORMER

(LOOP FEED)

UG1.02 SINGLE PHASE TWO BUSHING PADMOUNTED TRANSFORMER ONLY

UG1.3 (UG7) LOOP TYPE SINGLE PHASE TWO BUSHING PADMOUNTED

TRANSFORMER

UG2.1 (UX1) OPEN DELTA CONNECTION WITH SINGLE PHASE PADMOUNTED

TRANSFORMERS

THREE PHASE THREE BUSHING PADMOUNTED TRANSFORMER

(RADIAL FEED)

UG3.01 THREE PHASE THREE BUSHING PADMOUNTED TRANSFORMER ONLY

UG3.1 (UG17) RADIAL TYPE THREE PHASE THREE BUSHING PADMOUNTED

TRANSFORMER

UG3.2 (UG17-3) THREE PHASE SIX BUSHING PADMOUNTED TRANSFORMER

(RADIAL FEED)

THREE PHASE SIX BUSHING PADMOUNTED TRANSFORMER

(LOOP FEED)

UG3.02 THREE PHASE SIX BUSHING PADMOUNTED TRANSFORMER ONLY

UG3.3 (UG17-2) LOOP TYPE THREE PHASE SIX BUSHING PADMOUNTED

TRANSFORMER

TRANSFORMER ASSEMBLY UNITS







INDEX UH

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UH.01 (UM6-6) GROUND ROD ASSEMBLY

UH1.1 (UM48-1) GROUNDING ASSEMBLY FOR PADMOUNTED TRANSFORMERS

AND ENCLOSURES (1 ROD)

UH1.2 (UM48-2) GROUNDING ASSEMBLY FOR PADMOUNTED TRANSFORMERS

AND ENCLOSURES (2 RODS)

UH1.4 (UM48-5) GROUNDING ASSEMBLY FOR PADMOUNTED TRANSFORMERS

AND ENCLOSURES (4 RODS)

UH1.7 (UM48-6) GROUND ARRAY FOR PADMOUNTED TRANSFORMERS AND 

ENCLOSURES

UH2.0 COUNTERPOISE GROUNDING

UH2.2

UH2.7 TRENCH TYPE GROUNDING ASSEMBLY - RISER TO TRANSFORMER

OUTSIDE OF CONDUIT

UH3.1 (UX5) GROUNDING ASSEMBLY FOR SECTIONALIZING ENCLOSURES

(1 ROD)

UH4.1 (UX4) GROUNDING ASSEMBLY FOR CABLE ABOVE GRADE ENCLOSURES

(1 ROD)

UH4.1G (UM6-39) JACKETED CABLE GROUNDING INSTALLATION

(HEAT SHRINK OR COLD SHRINK)

GROUNDING ASSEMBLY UNITS










INDEX UJ

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UJ1.01 (UM6-32) SECONDARY SPLICE

UJ1 (UJ1) SECONDARY INSULATED CONNECTOR BLOCKS

UJ2 (UJ2) TRANSFORMER CONNECTOR BLOCKS

UJ3.1 (UK5) SECONDARY PEDESTAL SINGLE PHASE UNDERGROUND CABLE

UJ3.3 SECONDARY PEDESTAL THREE PHASE UNDERGROUND CABLE

UJ4.1 (UK6) SECONDARY HANDHOLE SINGLE PHASE UNDERGROUND CABLE

UJ4.3 SECONDARY HANDHOLE THREE PHASE UNDERGROUND CABLE

SECONDARY ASSEMBLY UNITS







INDEX UK

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UK1.1 (UM5) SECONDARY CABLE RISER POLE WITHOUT METER BASE

UK2.1 SECONDARY RISER BOTTOM CONNECTION

UK2.2 SECONDARY RISER BOTTOM SIDE CONNECTION

UK3.1 (UX8) TEMPORARY CONDUIT TERMINATION WITHOUT METER BASE

UK4 SECONDARY BREAKER

SECONDARY SERVICE ASSEMBLY UNITS





INDEX UM

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UM1.XX RIGHT-OF-WAY CLEARING

UM2 (UM6-12) CABLE ROUTE MARKER

UM3 SAFETY SIGNS

CAPS AND PLUGS

UM6.C2 (UM6-10) INSULATED PROTECTIVE CAP - 200 AMP LOAD BREAK

UM6.C6 (UM6-11) INSULATED PROTECTIVE CAP - 600 AMP DEAD BREAK

UM6.PL2 (UM6-7) BUSHING WELL PLUG - 200 AMP LOAD BREAK

UM6.PL6 (UM6-17) INSULATING PLUG TEE CONNECTOR - 600 AMP DEAD BREAK

ELBOWS

UM6.EL2 (UM6-1) LOAD BREAK ELBOW - 200 AMP LOAD BREAK

UM6.EL2F (UM6-2) FUSED ELBOW TERMINATION - 200 AMP LOAD BREAK

UM6.EL6 (UM6-3) DEAD BREAK ELBOW TERMINATION - 600 AMP

UM6.EL9 (UM6-3) DEAD BREAK ELBOW TERMINATION - 900 AMP

UM6.FI (UM6-4) FAULT INDICATORS

INSERTS

UM6.IN22 (UM6-5) FEED THROUGH INSERT - 200 AMP LOAD BREAK

UM6.IN2 (UM6-13) LOAD BREAK INSERT - 200 AMP LOAD BREAK

UM6.IN6 (UM6-14) DEAD BREAK INSERT - 600 AMP DEAD BREAK

MULTIPOINT JUNCTIONS

UM6.JN22 (UM6-20) TWO POINT TERMINATION, 2-200 AMP LOAD BREAK

UM6.JN222 (UM6-21) THREE POINT TERMINATION, 3-200 AMP LOAD BREAK

UM6.JN2222 (UM6-22) FOUR POINT TERMINATION, 4-200 AMP LOAD BREAK

UM6.JN6226 FOUR POINT TERMINATION, 2-600 AMP DEAD BREAK AND

2-200 AMP LOAD BREAK

MISCELLANEOUS ASSEMBLY UNITS
INDEX UM (Cont.)

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

PARKING STANDS

UM6.PK2 (UM6-15) STAND OFF INSULATOR

UM6.PKGD ONE POINT GROUND

UM6.PK22 (UM6-19) STAND OFF INSULATOR FEED THROUGH - 200 AMP

PRIMARY TERMINATIONS

UM6.RK HEAT SHRINK OR COLD SHRINK TUBING

UM6.SP (UM6-28) IN LINE PRIMARY SPLICE

UM6.T (UM6-24) OUTDOOR TERMINATION

UM6.TS (UM6-26) INDOOR STRESS RELIEF CONE

MISCELLANEOUS ASSEMBLY UNITS










INDEX UO

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UO1 OUTDOOR LIGHT INSTALLATION GUIDE

UO2 LIGHT STRUCTURE INSTALLATION GUIDE

OUTDOOR LIGHTING ASSEMBLY UNITS
UO1 . 100 MH . A4
UO2 . 100 HPS . A
INDEX UP

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

ARRESTERS

UP1 (UM6-33) RISER POLE ARRESTER

UP2 (UM6-34) ELBOW ARRESTER

UP3 (UM6-38) BUSHING ARRESTER

ARRESTERS AND ANODES

UP4 (UM6-37) PARKING STAND ARRESTER

UP5 (UM27-1,-2,-3) SACRIFICAL ANODES

(UM28)

UP7.01 (UM6-8) RISER SHIELD

UP7.02 (UM6-18) BACK PLATE

UP7.03 (UM6-9) CONDUIT CABLE RISER

UP7.04 CONDUIT ELBOW

UP7.B1 SINGLE CONDUIT RISER WITH STAND-OFF BRACKETS

UP7.B2 TWO CONDUIT RISER WITH STAND-OFF BRACKETS

UP7.B3 THREE CONDUIT RISER WITH STAND-OFF BRACKETS

UP7.C STRAP ATTACHED CONDUIT RISER

UP7.FC FLEX CONDUIT RISER

UP7.UG U-GUARD RISER

UP8 UNDERGROUND CONDUIT

SYSTEM PROTECTION ASSEMBLY UNITS











INDEX UQ

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UQG METER OPTIONS GUIDE

UQ_._B_ (UM8) METER ON BUILDING

UQ_._P_ (UM8-3,-3A) TROUGH TYPE METER PEDESTAL

UQ_._S_ (UM8-2) METER PEDESTAL WOOD POST

UQ_._T_ (UM8-4,-4A) METER PEDESTAL AT TRANSFORMER

METERING ASSEMBLY UNITS




INDEX UR

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UR3.-- THREE PHASE PADMOUNTED RECLOSER

RECLOSER ASSEMBLY UNITS

INDEX US

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

US1.DC SINGLE PHASE PADMOUNTED TRANSFORMER DEFERRED UNIT

CABINET TYPE

US1.DP (UX2) SINGLE PHASE PADMOUNTED TRANSFORMER DEFERRED UNIT

PEDESTAL TYPE

US1.DV (UX3) SINGLE PHASE PADMOUNTED TRANSFORMER DEFERRED UNIT

PAD-SLEEVE TYPE

SINGLE AND THREE PHASE PRIMARY JUNCTIONS

US1.PJ (UM3-14) SINGLE PHASE PRIMARY JUNCTION

US3.PJ (UM33) THREE PHASE PRIMARY JUNCTION

US_.SF_ (UM3E-_-_) SWITCH / FUSE ENCLOSURE INSTALLATION

US1.SF_ (UM3E-1) SINGLE POLE SWITCHING 200 AMP FUSE ENCLOSURE INSTALLATION

US2.SF_ (UM3E-2) WIRING DIAGRAMS (SINGLE PHASE AND TWO PHASE)

US3.SF_ (UM3E-3) FUSE ENCLOSURE (200-600 AMP) WIRING DIAGRAMS (THREE PHASE)

SECTIONALIZING ASSEMBLY UNITS







INDEX UT

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

TRENCHES FOR CONDUIT AND DIRECT BURIAL CABLES

UT1 (UR2) TRENCH

UT2 TRENCH WITH CONCRETE ENCASEMENT

UT3 TRENCH WITH CONCRETE CAP

UT4 TRENCH - DIRECTIONAL BORE

UT5 TRENCH - PLOW

TRENCH ASSEMBLY UNITS

INDEX UY

DRAWING NUMBERS DRAWING TITLE (DESCRIPTION)

1728F-806

(New)

1728F-806

(Old)

UY1.1XX SINGLE PHASE PADMOUNTED VOLTAGE REGULATOR WITH

NO BYPASS SWITCH

UY1.1.XXSW SINGLE PHASE PADMOUNTED VOLTAGE REGULATOR WITH 

BYPASS SWITCH

UY3.2L THREE PHASE PADMOUNTED SHUNT REACTOR WITH LOOP FEED

UY3.3L THREE PHASE PADMOUNTED CAPACITOR WITH LOOP FEED

VOLTAGE CONTROL ASSEMBLY UNITS


.

Bulletin 1728F-806

Exhibit 1

Page 1

Old

Assembly 

Number

(June 2000 1728F-806)

New 

Assembly 

Number

(1728F-806)

Material Changes

and

Comments

UA1 UA1 Removed cable riser shield and separated into new UP unit

UA2 UA2 Removed cable riser shield and separated into new UP unit

UA3 UA3 Removed cable riser shield and separated into new UP unit

UB1 UB1 Removed cable riser shield and separated into new UP unit

UB2 UB2 Removed cable riser shield and separated into new UP unit

UB3 UB3 Removed cable riser shield and separated into new UP unit

UB4 UB4 Removed cable riser shield and separated into new UP unit

UC1 UC1 Removed cable riser shield and separated into new UP unit

UC2 UC2 Removed cable riser shield and separated into new UP unit

UC2-1 UC6 Removed cable riser shield and separated into new UP unit

UC2-2 UC6 Removed cable riser shield and separated into new UP unit

UC5-1 UC7.2 Combined deadend and tangent terminal pole units

UC6-1 UC7.2 Combined deadend and tangent terminal pole units

UG6 UG1.1 Add elbow, bushing arrester, and secondary connector blocks

UG7 UG1.3 Add elbows and secondary connector blocks

UG17 UG3.1 Add elbows, bushing arresters, and secondary connector blocks

UG17-2 UG3.3 Add elbows, elbow arresters, and secondary connector blocks

UG17-3 UG3.2 Add elbow arresters and secondary connector blocks

UJ1 UJ1 No Material Changes - Separated Drawings

UJ2 UJ2 No Material Changes - Separated Drawings

UK5 UJ3.1 No material changes

UK6 UJ4.1 No material changes

UM1-5C UF1.PC No material changes

UM1-5NC UF1.PN No material changes

UM1-6C UF3.PC No material changes

UM1-7C UF1.BC No material changes

UM1-7NC UF1.BN No material changes

UM3-14 US1.PJ No material changes

UM3-44 Discontinued

UM3-45 Discontinued

UM3-46 Discontinued

UM3E-_-_ US_.SF_ No material changes

UM3E-1 US1.SF_ No material changes

UM3E-2 US2.SF_ No material changes

UM3E-3 US3.SF_ No material changes

UM5 UK1.1 Removed cable riser shield and separated into new UP unit

UM5-6 Discontinued

UM5-6A Discontinued

Disposition of Assemblies in Bulletin D-806
Bulletin 1728F-806

Exhibit 1

Page 2

Old

Assembly 

Number

(June 2000 1728F-806)

New 

Assembly 

Number

(1728F-806)

Material Changes

and

Comments

UM6-1 UM6.EL2 No Material Changes

UM6-2 UM6.EL2F No Material Changes

UM6-3 UM6.EL6/9 No Material Changes

UM6-4 UM6.FI No Material Changes

UM6-5 UM6.IN22 No Material Changes

UM6-6 UH1.01 No material changes

UM6-7 UM6.PL2 No Material Changes

UM6-8 UP7.01 No material changes

UM6-9 UP7.03 No material changes

UM6-10 UM6.C2 No Material Changes

UM6-11 UM6.C6 No Material Changes

UM6-12 UM2 No Material Changes

UM6-13 UM6.IN2 No Material Changes

UM6-14 UM6.IN6 No Material Changes

UM6-15 UM6.PK2 No Material Changes

UM6-17 UM6.PL6 No Material Changes

UM6-18 UP7.02 No material changes

UM6-19 UM6.PK22 No Material Changes

UM6-20 UN6.JN22 No Material Changes

UM6-21 UM6.JN222 No Material Changes

UM6-22 UM6.JN2222 No Material Changes

UM6-24 UM6.T No Material Changes

UM6-26 UM6.TS No Material Changes

UM6-28 UM6.SP No Material Changes

UM6-32 UJ1.01 No Materal Change

UM6-33 UP1 No Materal Change

UM6-34 UP2 No Materal Change

UM6-35 Discontinued, refer to Overhead Specifications

UM6-36 Discontinued, refer to Overhead Specifications

UM6-37 UP4 No Materal Change

UM6-38 UP3 No Materal Change

UM6-39 UH4.1G Modified guide drawing; no material

UM7-1 Discontinued

UM8 UQ_._B_ No Materal Change

UM8-2 UQ_._S_ No Materal Change

UM8-3 UQ_._P_ No Materal Change

UM8-3A UQ_._P_ No Materal Change

UM8-4 UQ_._T_ No Materal Change

Disposition of Assemblies in Bulletin D-806
Bulletin 1728F-806

Exhibit 1

Page 3

Old

Assembly 

Number

(June 2000 1728F-806)

New 

Assembly 

Number

(1728F-806)

Material Changes

and

Comments

UM8-4A UQ_._T_ No Materal Change

UM8-5 Discontinued

UM8-6 Discontinued

UM8-7 Discontinued

UM9-2 Discontinued

UM12 Discontinued, combined with UM2

UM27-1 UP5.2 No material changes

UM27-2 UP5.3 No material changes

UM27-3 UP5.4 No material changes

UM28 UP5.1 No material changes

UM33 US3.PJ Add junction modules

UM48-1 UH1.1 No material changes

UM48-2 UH1.2 No material changes

UM48-3 Discontinued

UM48-4 Discontinued

UM48-5 UH1.4 No material changes

UM48-6 UH1.7 No material changes

UR2 UT1-UT5 Modified trenching drawing, refer to UT1 - UT5

UR2-1 UT1-UT5 Modified trenching drawing, refer to UT1 - UT5

UR2-2 UT1-UT5 Modified trenching drawing, refer to UT1 - UT5

UR2-3 UT1-UT5 Modified trenching drawing, refer to UT1 - UT5

UR2-4 UT1-UT5 Modified trenching drawing, refer to UT1 - UT5

UR2-5 UT1-UT5 Modified trenching drawing, refer to UT1 - UT5

UR2-NT UT1-UT5 Modified trenching drawing, refer to UT1 - UT5

UR2-ST UT1-UT5 Modified trenching drawing, refer to UT1 - UT5

UX1 UG2.1 Add elbows, elbow arresters, and secondary connector blocks

UX2 US1.DP No material changes

UX3 US1.DV No material changes

UX4 UH4.1 Modified guide drawing; added material

UX5 UH3.1 Modified guide drawing; added material

UX7 Discontinued

UX8 UK3.1 No material changes

UX11 UA.G Arrester connection guide drawing

Disposition of Assemblies in Bulletin D-806
Bulletin 1728F-806

Exhibit 2

Page 1

NUMBER ASSEMBLY / GUIDE DRAWING DESCRIPTION

UA4 SINGLE PHASE CABLE TERMINAL POLE WITHOUT CUTOUT

UA.G CABLE TERMINAL POLE ARRESTER CONNECTION GUIDE

UA1.USG UNDERGROUND SOURCE CONNECTION GUIDE

UB5 TWO PHASE CABLE TERMINAL POLE WITH UPPER CROSSARM MOUNTING 

CUTOUTS AND CROSSARM MOUNTING ARRESTERS

UB6 TWO PHASE CABLE TERMINAL POLE WITH UPPER CROSSARM MOUNTING 

CUTOUTS AND BRACKET MOUNTING ARRESTERS

UC3 THREE PHASE TERMINAL POLE WITHOUT CUTOUTS AND CROSSARM 

MOUNTING ARRESTERS 

UC4 THREE PHASE TERMINAL POLE WITHOUT CUTOUTS AND BRACKET 

MOUNTING ARRESTERS 

UC5 THREE PHASE TERMINAL POLE WITH UPPER CROSSARM MOUNTING 

CUTOUTS AND CROSSARM MOUNTING ARRESTERS 

UC7.1 BRACKET MOUNTED SWITCHES

UC7.3 VERTICAL SWITCHES MOUNTED ON THREE CROSSARMS

UC7.4 VERTICAL SWITCHES MOUNTED ON FOUR CROSSARMS

UC8.1 THREE PHASE CABLE TERMINAL POLE WITH VERTICAL FRAMING AND 

TWO BRACKETS PER PHASE

UC8.2 THREE PHASE CABLE TERMINAL POLE WITH VERTICAL FRAMING AND 

ONE BRACKET PER PHASE

UF.PBC CONCRETE PRIMARY PULL BOX

UF.PBN NON-CONCRETE PRIMARY PULL BOX

UF3.BC CONCRETE BOX PAD FOR THREE PHASE EQUIPMENT

UF3.BN NON-CONCRETE BOX PAD FOR THREE PHASE EQUIPMENT

UF3.PN NON-CONCRETE PAD FOR THREE PHASE EQUIPMENT

UF3.VC CONCRETE VAULT FOR THREE PHASE EQUIPMENT

UG1.01 SINGLE PHASE ONE BUSHING PADMOUNTED TRANSFORMER ONLY

UG1.02 SINGLE PHASE TWO BUSHING PADMOUNTED TRANSFORMER ONLY

UG1.2 SINGLE PHASE TWO BUSHING PADMOUNTED TRANSFORMER - RADIAL 

FEED

UG3.01 THREE PHASE THREE BUSHING PADMOUNTED TRANSFORMER ONLY

UG3.02 THREE PHASE SIX BUSHING PADMOUNTED TRANSFORMER ONLY

NEW TWO PHASE RISER POLE ASSEMBLY UNITS

NEW THREE PHASE RISER POLE ASSEMBLY UNITS

Bulletin 1728F-806: New Assemblies and Guide Drawings

NEW TRANSFORMER ASSEMBLY UNITS

NEW FOUNDATION ASSEMBLY UNITS

NEW SINGLE PHASE RISER POLE ASSEMBLY UNITS
Bulletin 1728F-806

Exhibit 2

Page 2

NUMBER ASSEMBLY / GUIDE DRAWING DESCRIPTION

UH2.0 COUNTERPOISE GROUNDING

UH2.2 COUNTERPOISE GROUNDING

UH2.7 TRENCH TYPE GROUNDING ASSEMBLY - RISER TO TRANSFORMER 

OUTSIDE OF CONDUIT

UH4.1G JACKETED CABLE GROUNDING INSTALLATION

(HEAT SHRINK OR COLD SHRINK)

UJ3.3 SECONDARY PEDESTAL THREE PHASE UNDERGROUND CABLE

UJ4.3 SECONDARY HANDHOLE THREE PHASE UNDERGROUND CABLE

UK2.1 SECONDARY RISER BOTTOM CONNECTION

UK2.2 SECONDARY RISER BOTTOM SIDE CONNECTION

UK4 SECONDARY BREAKER

UM1.XX RIGHT-OF-WAY CLEARING

UM3 SAFETY SIGNS

UM6.JN6226 FOUR POINT TERMINATION, 2-600 AMP DEAD BREAK AND 2-200 AMP LOAD 

BREAK

UM6.PKGD ONE POINT GROUND

UM6.RK HEAT SHRINK OR COLD SHRINK TUBING

UO1 OUTDOOR LIGHT INSTALLATION GUIDE

UO2 LIGHT STRUCTURE INSTALLATION GUIDE

UP7.04 CONDUIT ELBOW

UP7.B1 SINGLE CONDUIT RISER WITH STAND-OFF BRACKETS

UP7.B2 TWO CONDUIT RISER WITH STAND-OFF BRACKETS

UP7.B3 THREE CONDUIT RISER WITH STAND-OFF BRACKETS

UP7.C STRAP ATTACHED CONDUIT RISER

UP7.FC FLEX CONDUIT RISER

UP7.UG U-GUARD RISER

UP8 UNDERGROUND CONDUIT

UQG METER OPTIONS GUIDE

UR3.-- THREE PHASE PADMOUNTED RECLOSER

NEW SYSTEM PROTECTION ASSEMBLY UNITS

NEW MISCELLANEOUS ASSEMBLY UNITS

NEW OUTDOOR LIGHTING ASSEMBLY UNITS

NEW RECLOSER ASSEMBLY UNITS

NEW METERING ASSEMBLY UNITS

NEW SECONDARY ASSEMBLY UNITS

NEW SERVICE ASSEMBLY UNITS

Bulletin 1728F-806: New Assemblies and Guide Drawings

NEW GROUNDING ASSEMBLY UNITS
Bulletin 1728F-806

Exhibit 2

Page 3

NUMBER ASSEMBLY / GUIDE DRAWING DESCRIPTION

US1.DC SINGLE PHASE PADMOUNTED TRANSFORMER DEFERRED UNIT - CABINET 

TYPE

UT2 TRENCH WITH CONCRETE ENCASEMENT

UT3 TRENCH WITH CONCRETE CAP

UT4 TRENCH - DIRECTIONAL BORE

UT5 TRENCH - PLOW

UY1.1XX SINGLE PHASE PADMOUNTED VOLTAGE REGULATOR WITH NO BYPASS 

SWITCH

UY1.1.XXSW SINGLE PHASE PADMOUNTED VOLTAGE REGULATORS WITH BYPASS 

SWITCH

UY3.2L THREE PHASE PADMOUNTED SHUNT REACTOR WITH LOOP FEED

UY3.3L THREE PHASE PADMOUNTED CAPACITOR WITH LOOP FEED

NEW TRENCH ASSEMBLY UNITS

NEW VOLTAGE CONTROL ASSEMBLY UNITS

NEW SECTIONALIZING ASSEMBLY UNITS

Bulletin 1728F-806: New Assemblies and Guide Drawings
RUS Bulletin 1728F-806

 Attachment C

Page 1

Attachment C

RUS Standard Format and Meaning of Underground Distribution Assembly Numbers

The RUS standard numbering format for underground distribution assemblies is: UL1N1.LN2

L1 is an alphabetic character that represents the category or group of similar assemblies that fulfill a similar 

and specific function in the construction or operation of an underground distribution line. For example, 

the assemblies in category “C” are pole top riser assemblies that support three primary cables, 

terminations, arresters and cutouts/switches.

The following table shows the 16 distribution assembly categories and the letter (UL1) RUS has assigned 

to represent them.

DESIGNATED MEANINGS of ASSEMBLY CATEGORY NUMBERS (UL1)

UA 1-Phase, pole-top 

riser

UB 2-Phase, pole-top 

riser

UC 3-Phase, pole-top 

riser

UF Foundations

UG Transformers

UH Grounds

UJ Secondaries

UK Services

UM Miscellaneous

UO Outdoor Lighting

UP Protection

UQ Metering

UR Reclosers

US Sectionalizing

UT Trench

UY Volt. Alteration 

Equip.

N1 is a numeric character that represents a subcategory or group of similar assemblies within a category. 

The different assemblies in a subcategory all fulfill the same specific functional purpose, but their function 

is somewhat different than the other assemblies within their associated assembly category (UL1). It may 

represent selected material and arrangement to accomplish the function or it could represent the number 

of phases involved to accomplish a similar purpose.

The following table shows the RUS designated meaning of the numbers (N1) that represent the 

pole-top riser assembly category “A”.
RUS Bulletin 1728F-806

 Attachment C

Page 2

DESIGNATED MEANINGS of SUBCATEGORY

NUMBERS (N1) for POLE TOP RISER ASSEMBLIES

1 Single phase cable terminal pole top with two brackets

2 Single phase cable terminal pole top with one bracket

3 Single phase cable terminal pole top with crossarm mounted 

cutout

4 Single phase cable terminal pole top without cutout

RUS has assigned meanings to the subcategory numbers (N1) for the remaining 15 (UL1) categories of 

underground distribution assemblies, however, the list and meanings of these numbers is long and varied 

and beyond the scope of this summary exhibit. The index for each section in this bulletin defines the 

assembly unit for each Construction Assembly Unit.

LN2, which is either one or two letters or numbers, is defined as the assembly identification. This 

identification is used to differentiate the similar assemblies in a subcategory (N1) of assemblies. The 

assigned meanings to assembly identification vary between categories. The use between categories is 

explained in the Subcategory index.

For example, in underground there are several parts that are used to connect many different pieces of 

padmounted equipment under several categories. These are grouped under miscellaneous UM6 with 

letters identifying the type of device and suffixes indicating the number, size and type of interface.

DESIGNATED MEANINGS of ASSEMBLY IDENTIFICATION

NUMBERS (N2) for MISCELLANEOUS ASSEMBLIES (UM6)

C Cap

EL Elbow

FI Fault Indicator

IN Insert

JN Junction Module

PK Parking Stand

PL Plug

T Terminator

SP Splice

RK Reseal Kit

The prefix “25” in front of a standard assembly number indicates that the assembly is used for 24.9/14.4 

kV underground construction. A standard assembly number with prefix “15” indicates that the assembly 

is used for 12.47/7.2 kV underground construction.

A suffix is an alphabetic character or number placed at the end of a standard assembly number. A suffix 

describes the type of the assembly. The following are some typical suffixes.

G (Guide drawing, not an assembly) 2 200 Amp Load Break
RUS Bulletin 1728F-806

 Attachment C

Page 3

C (Concrete) 6 600 Amp Dead Break

N (Non Concrete) 9 900 Amp Dead Break

Not all assembly numbers have suffixes and some may have more than one suffix number or letter.

SUMMARY

Each unit will use the same format. The VOLTAGE PREFIX, when required is followed by the 

ASSEMBLY CATEGORY, a two-letter designation UA through UY which represent single phase 

primary units through voltage control units. Sometimes numbers complete the assembly category. After 

the assembly category a DOT (.) is inserted before the ASSEMBLY IDENTIFICATION. The assembly 

identification uses both numbers and letters to identity a unit within the category. Note subunits use a 

zero before the number and represents parts for a larger unit. Sometimes a SUFFIX DESIGNATION is 

required to provide further clarification.