INDUSTRIAL DISTRIBUTION

TRANSFORMERS

Sujit Das

Energy and Global Change

Analysis Section

Energy Division

Presented To:

Quarterly Review

Meeting

Distribution Transformer

Determination Study

Oak Ridge, TN

June 13, 1994

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The Non-Utility Distribution Transformer Industry

Annual Production Volume: 330,000 Units (90% Drytype; 10% Liquid-type)

Dry-Types Are Only Used in This Sector

Life -- Dry-Types (20 Years) -- Liquid-Types (25 Years)

Higher A Are Generally Three-Phase

Usually Oversized for Reliability (Of the Total 33%

Underloaded, 28% Are in This Sector)

Losses Are Higher Than in the Utility Sector

Competition Has Driven Higher Efficiency in Low

Voltage Transformers

Numerous Small Specialized Dry-Type Transformer

Manufacturers (100+)

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SINGLE-PHASE TRANSFORMER LOSSES

No Load LossUtility

Load LossUtility

No Load LossNon-Utility

Load LossNon-Utility

Load LossDry-Type

No Load LossDry-Type

10 15 25 37.5 50 75 100 167 250 333 500

KVA C:,IJA-,.CH,

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25,000

20,000

?' 15,000

5,000

THREE-PHASE TRANSFORMER LOSSES

45 112. 5 225 500 1500 2500

75 150 300 1000 2000

KVA

0

No Load LossUtility

Load LossUtility

No Load LossNon-Utility

Load Losson-Utility

--A--

Load LossDry-Type

No Load LossDry-Type

CAFL\KVA-2.CH,

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Energy Losses Are Not the Main Concern in the Commercial

Sector

First Cost Is the Main Criteria

Buyer Is Not the User

Sales Are Done Through Distributors

A & B Factors are generally 0/0 (A Study Reported

2.6/1.6)

Loss Factor (Relates Average To Peak Loss) Around

54% (20% In the Case of Residential)

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The Industrial Sector Is Concerned About Energy Losses

Total TOC Criteria Used With Varied A & B Factors

No-Load Factor -- 2.5-7.0 (Avg. 4.5)

Load Factor -- 0.0-4.0 (Avg. 1.0)

Very Sensitive to No-Load Losses (Non-Uniform

Loading, Oversizing)

Oversizing Preferred (Motor Start-Up, Reliability,

Longer Life, and Less Load Losses)

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Typical Specifications Indicated for Dry-Type Distribution

Transformers

Insulation Systems (Temp. Rise)

Core/Coil Assemblies

Enclosures

Sound Levels

Tests (Ratio, Polarity, Phase-Relation, and Applied and

Induced Potential)

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Prices of Dry-Type Distribution Transformers

0 100 300

A

400

Temp. rise 80 C Temp. rise 115 C

200

------A------

500

3 phase, 60 Hz, 480 volts to 240 volts

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A Few Initial oughts ...

Little or No Data (Particularly for Dry-Type) Are

Currently Available (Extensive Data Collection Is

Necessary)

Data Collection May Be Little Difficult (Too Many

Players)

National Perspective of A And B Factors Is Necessary

(Only Differences from The Utility Sector Are Peak

Load Responsibility and Loss Factors and Tax

Structures)

Energy Conservation Potential Seems to Be Higher

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Energy Conservation Cases for the Determination Study

Cases Could Be Developed Either Based on Losses

and/or AB Factors

Base Case 25 kVA

Oil: NL = 79, LL - 486

Dry: NL = 157, LL - 982

CSA - C802-94 25 kVA

Oil: NL - 73, LL - 406

Dry: NL- 150, LL - 900

National Perspective

Oil: A/B

Dry:

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Progress Made So Far ...

Initial Industry Contacts Made

Data Collection Initiated

Possible Energy Conservation Cases Looked Into

Preliminary Analysis Started

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