Distribution Transforir

Workshop

10-Feb 98

Kathi Epping.

ier

Distribution Transform r 

.. Workshop . ' . 

IO'Feb 98 

Kathi Epping 
CONSENSU;; STANDARL;,

ANSI. C57.12.90-1993, "IEEE Standards s Test Code' for Li ui -

I ersed Distribution, Power and , egulating Transfo rmers and IEEE

Guide for Short Circuit Testing of Distribution. and Power

Transformers"

ANSI 057. 12.91-1995 , "IEEE Standard Test Code for Dry-Type

Distribution and Power Transformers"

ANSI C57-.12.00-1993,-"IEEE Standard General require m ents for

Liquid-Immersed Distribution, Power and Regulating Transformers"'

ANSI 057.12.01-1989, "IEEE Standard General Requirements for.

Dry-Type Distribution and Power Transformers, including those with

Solid Cast and/or Resin-Encapsulated Windings""

CON,SENSUS STANDARDS 

\ 

\ 

., ANSLC57.12.90-1993, "IEEE Standards Test Code for LiquidImmersed Distribution, Power and 'Regulating Transfomiers and IEEE 

Guide for Sliort Circuit Testing.ofDistributionand Power " 

Transformers" ' , , " 

• 'ANSI C57.l2.91-1995, "IEEE Standard Test Code for Dry-Type 

Distribution and Power Transformers" 

• ANSI' C57.12.00-1993,"I~EE Standard General requirements for 

Liquid-Immersed Distribution, Power and Regulating Transformers" 

., ANSI C57.12.01-1989, "IEEE Standard GeneralRequirements for, 

Dry-Type Distribution and Power Transformers, includingthose with 

Solid Cast and/or Resin-Encap~ulated Windings" -
Unofficial Is

NEMA Draft TP 2, "Standard Test Method

for Measuring the Energy Consumption of

Distribution Transformers"

IEEE PC57. 123, "Draft Guide for

Transformer Loss Measurement"

... Unofficial tand rds 

• NE:MA Draft TP 2, "Standard Test Method 

for Measuring.the Energy Consumption of 

. Distribution Transfonners" 

• ·IEE·E PC57.123,."Draft Guide for . 

. Transfonner Loss Measurement"·· 
Are the consensus standards appropriate for

referencing as the DOE-required test practice?

• Is the clause-by-clause referencing of ANSI

standards. in. the NIST Draft, pp. 16-20, too

detailed? Should it be abbreviated by referencing

only the appropriate sections in the two test

codes those describing dc resistance, no-load

- loss, and load loss measurements-and alluding to

the specific causes where exceptions are made?

Consensus tandards 

• Are the consensus standards approp~iate for 

referencing as th~_QOE-required test practice? 

• Is theclause-by-clause r~ferencing of ANSI 

standards in-the NIST Draft, pp. 16-20, too _ 

detailed? Should it be abbreviated by referencing -

only the appropriate sections inthe two test 

codes-those <.iesctibing dc resistance, no-load 

-loss, -and load loss measurements- __ and alluding to 

the- specific clauses where exceptions are-made? 
Conse1 us Stanza

Should additional relevant standards now in

preparation and approval stages, such as

IEEE PC57. 123/D 1 A "Draft Guide for

Transformer Loss Measurement" & NE

TP2 be considered additional or alternative

references? Will they add to the knowledge

base of the already existing consensus

standards or enhance the user convenience?

. Consensus tandards 

- . . . . 

• . ·Should additional relevant standards now in 

preparation and C!pproval stages,. such as-- / . 

IEEE PC57.123/Dl.l "Draft Guide for 

Transformer Loss Measurement" & NEMA 

TP ... 2be considered additional or alternative ' 

references? Will they add to the knowledge 

. base of the already existing consensus-· 

standards or enhance the user convenience? 
Basic Model

Basic model means all units of a given type of

covered equipment (or class thereof)

manufactured by a single manufacturer and, with

respect to distribution transformers, which have

the same rating, have electrical characteristics that

are essentially identical, - and do not have any

differing physical or electrical characteristics

which .affect energy consumption or efficiency.

Basic Model Definition 

• Basic model means all units of a given type of 

covered equipment (or class thereof) 

manufacture.d by a single manufacturer and, with 

respect to distribution transformers,_ which have 

'. the same rating, have electrical characteristics that 

are essentially identical,~ and do not have anydiffering physical or electrical characteristics 

which affect energy consumption or efficiency.· .' 
Bas

ic M

-

view ion for a "basic model

,

"

do you anticipate significant difficulties in

grouping-your products into basic

r those manufacturers having items

per model, would it possible . . , a

number of * is I'nto families s 6f basic models,

®, grouping many actual production'

the s.a nominal kVA, rating in one family of -

models?

Basic Model 

• In view of such a definition for a "basic model," - , 

do you anticipate significant difficulties in , ' 

grouping your products into:basic models? 

,. For those manufacturers having only ~ few itemsper model, would it be possible to combine a ' 

number of models into families of basic models, 

e.g.,'grouping many actual production 'models of 

the s_amenominal kV A rating in one family of' 

models? 
• Would it be possible to combine similar

manufacturing models, e.g., having the

same nominal kVA rating, in one "basic

model" by using normalized loss data?

Basic· od 1 ... 

, 

• Would it be possible to combine similar 

manufacturing models, e.g., having the 

same nominal kVA rat'ing, in one "basic 

model" by using normalized los's data? 
"Loss Percentage (LP)" defined as

=100[1+(ALwhere AL represents actual measured total

losses, and ML represents mandated

maximum total losses

Such an approach appears to be valid for X1 1

manufacturing models having sim i

lar

variability for (AL/Mt)0

~ 

. Basic Model- normalized losses 

• "Loss Percentage (LP) " defined as.· 

LP== 100 [1 +( AL-ML )/ML 

• where AL. represents actuall11easured total 

.. losses, andML represents mandated 

maximum total losses -

• Such an approach appears to be valid for all .. 

manufacturing· models having similar 

variability for (AL/ML). 
ampling r an

Please provide comments on the two

sampling plans DOE is considering for

compliance testing.

Please describe other approaches you

believe DOE should consider.

Sampling Plan 

• Please provide COlTIlTIents on the two. 

sampling plans DOE is considerin.g for 

cotnplianc.e. testing . 

• ' Please describe other approaches you 

. believe DOE should consider. 
Measure of Energy Con

• Are there any strong reasons why efficiency

should not be used?

• Should other: measures of energy consumption be

considered: e.g., loss power normalized relative

to output kVA, ether onper unit basis or

percentage basis?

• Is reporting of efficiency and losses at reduced

loading levels appropriate for an energy

conservation standard?

easure of Energy Consumption 

• ,Are th~re any strong reasons why efficiency 

- -should not be used? 

• Should other'measures of energy consumption be 

considered: e.,g., loss power normalized relative 

. to output kV A, eithe:r on per unit basis or " 

percentage basis? 

• Is reporting of efficiency and losses at"reduced 

loading levels appropriate for an 'energy 

conservation standard? 
What specific requirements- in the NIST

draft test procedure are, causing concern

about significant additional burden i ^^ , used

by testing requirements?

Industry urden 

, -

..• What specific requirements· in the.NIST 

. draft test procedure are causing concern . 

ab-out significant additional burden imposed 

. by testing requirements? 

. 1 
Reference T IITIDtt^ratuj,(

20°C for No Load, both Liquid-Immersed &

Dry Type

• Single Reference Temp. . of 75°G for Load

for Dry-Type

55°C for Liquid-Immersed at 50% Load

~ . . 

. Reference Temp ratures 

• 200 e for No Load, both Liquid-Immersed 

Dry-Type 

.• Single Reference Temp.of75°C for Load 

for Dry-Type 

• 55°e for Liquid-Immersed at 50% Load 
Correc

• Using G.57.12.90

Load loss correction due to phase angle fw

both liquid and dry-type

No load loss corrected to reference

temperature of 20oC

Corrections 

- - . . 

. -Using C.57.12.90 

• Load loss correction due to phase angle for 

both liquid and dry-type 

- No load loss corrected to reference 

temperature of 200C . 

. 
Quality Ass

C57. i 2.00 Measurement Uncertainty

Are - there concerns- about applying

measurement accuracy requirements to dry

ype transformers (as is now done for

liquid-immersed) and about including a

clause for guidance from ISO 9001-1993 on

measurement quality assurance procedures?

Quality Assurance 

• ·C57.12.00 Measurement Uncertainty· I _ " . 

- . 

Tolerances 

•. Are there concerns about applying 

measurement accuracy requirements to dry-

...• type transformers . (as is now done for 

liquid-immersed) and about including a . . . 

clause for guidance_from ISO '900,1.-1993 on 

··measurement quality assurance procedures? . ,