### Energy **Efficient Tr**  **ansformers** 

# EP **A/CEE Confer ence**  **on Energy Efficiency**

**The Backgr ound of NEMA**  **T P** 
**- 1**  Phil Hopkinson, P. E.

1 

# Manager , Tr ansformer Te chnology

Square D Company

### Energy **Efficient Tr**  **ansformers** 

# Backgr **ound of NEMA** 

**T P** 
**- 1** 

• Objective

• Approach

2 

# • Studies

• Standard

### Energy **Efficient Tr**  **ansformers** 

# Backgr **ound of NEMA** 

**T P** 
**- 1** 

• Doable with known technology **Objectives**

3 

# • Economical

-- Pays for itself

• Saves ener gy NEMA a nticipates high market acceptance

### Energy **Efficient Tr**  **ansformers** 

# Backgr **ound of NEMA** 

**T P** 
**- 1** 

• Apply total owning cost methods **Appr oach** 

4 

# • Use real loading assumptions and real costs as close as possible

• Determine best fit ef

ficiencies

### Energy **Efficient Tr**  **ansformers** 

# Backgr **ound of NEMA** 

**T P** 
**- 1** 

• Av erage ener gy cost 6.5¢/kwh

• Most people would support a 3

- 5 year payback 

# Studies **Squar e D** 
**-- Building Owners** 

5 

# • Most people would support a 3

- 5 year payback

• Loading (RMS equivalent) 35% for L V Dry 50% for all MV

transformers A 3

- 5 year payback is now the average requirement for most US utilities as well as building owners

### Energy **Efficient Tr**  **ansformers** 

# DOE’ **s Main Forr estal**  **Building**

**% Instantaneous Load kV**  **A Siz**  **e Quantity**  **Min. Max.**  **Av g.**  15 6 5 24 17 30 11 2 108 36

6 

# 45 39 8 76 30 75 25 1 58 29 11 2.5 6 19 69 44 225 2 26 26 26 58.1 Av g. 89 2 108 30 We ighted Av g. % (kV

A * Qty Av g. load)/T

otal kV A = 31 We ighted Av g. % load for 30

- 11 2.5 kV A ratings only = 32

### Energy **Efficient Tr**  **ansformers** 

# Backgr **ound of NEMA** 

**T P** 
**- 1** 

TO C = A (NL) + B (LL) + Sell price
A  $0.065/kwh x 8.76 khr/yr x 3 yr . = $1.71/watt 

# To **tal Owning Cost Factors** 

7 

# A  $0.065/kwh x 8.76 khr/yr x 3 yr . = $1.71/watt Note: Using present worth of inflation series, A = $1.50/watt B = $A/kwh x x Te mperature Correction Factor


# For L V transformer B ~ $0.15/watt For MV transformer B ~ $0.35/watt 100 %Load 2

### Energy **Efficient Tr**  **ansformers**

**Ref er**  **ence Condition Temperatur**  **e %**  **of Nam eplat**  **e Load** Low Vol tage 75  C 35% Me di um Voltage 75  C 50%

**Single Phase Three Phase**  **Effic iency**  **Efficie ncy** 



## Ta **ble 4**
**- 2**  **NEMA C**  **lass 1 Efficiency Levels for**  **D ry**  **- Ty**  **pe Distribution**  **Tr ansformers**  

# Backgr **ound of NEMA** 

**T P** 
**- 1** 

8 

# 8 **kVA Low Voltage**  **Me dium Voltage**  **kVA Low Voltage**  **Medium Voltage** 15 97.7 97. 15 97.0 96.8 25 98.0 97.9 30 97.5 97.3 37.5 98.2 98.1 45 97.7 97.6 50 98.3 98.2 75 98.0 97.9 75 98.5 98.4 112.5 98.2 98.1 100 98.6 98.5 150 98.3 98.2 167 98.7 98.7 225 98.5 98.4 250 98.8 98.8 300 98.6 98.5 333 98.9 98.9 500 98.7 98.7 500

--- 99.0 750 98.8 98.8 667

--- 99.0 1000 98.9 98.9 833

--- 99.1 1500

--- 99.0 2000

--- 99.0 2500

--- 99.1 8

### Energy **Efficient Tr**  **ansformers**

**Ref eren**  **ce Condi**  **tio n**  **Tem per**  **ature %**  **of Na**  **me pl**  **ate Load**  Load Loss 85  C 50% No L oad Loss 20  C 50% **Si ngl**  **e Pha**  **se Thr**  **ee Phase**  **kV A**  **Ef fic**  **ie ncy**  **kV A**  **Ef fic**  **ie ncy**  10 98. 3 15 98. 0 

## Ta **ble 4**
**- 1**  **NEMA Class 1 Efficiency Levels for**  **Liquid**
**- Filled Distribution T**  **ransformers** 

# Backgr **ound of NEMA** 

**T P** 
**- 1** 

9 10 98. 3 15 98. 0 15 98. 5 30 98. 3 25 98. 7 45 98. 5 37. 5 98. 8 75 98. 7 50 98. 9 112. 5 98. 8 75 99. 0 150 98. 9 100 99. 0 225 99. 0 167 99. 1 300 99. 0 250 99. 1 500 99. 1 333 99. 2 750 99. 2 500 99. 3 1000 99. 2 667 99. 4 1500 99. 3 833 99. 4 2000 99. 4 2500 99. 4

### Energy **Efficient Tr**  **ansformers** 

# 75kV **A Tr**  **ansformer**

**E fficiency** 

**Ty pical**  **Energy Losses for**  **75 kV A**  **Low Vo**  **ltage Dry**  **Ty pe**  **Tr ansformer**  **Energy Efficiency**  **vs. 150oC Rise or**  **80oC Rise**  **No Load Load**  **To tal**  **Tr ansformer**  **Ty pe**  **Core Loss**

**(W atts)**  **100% Coil** 

**Loss (W**  **atts) 35%**  **Coil**

**Loss (W**  **atts) 100%**  **To tal** 

**Loss (W**  **atts) 35%**  **To tal** 

**Loss (W**  **atts)** 

## EXAMPLE

10 **Ty pe**  **(W atts)**  **Loss (W**  **atts) Loss**  **(W atts)**  **Loss (W**  **atts) Loss**  **(W atts)**  **Std 150oC**  **Rise** 460 2500 250 2960 710 **Std 80oC Rise**  800 960 96 1760 896 **TP1 Compliant**  **Energy Efficient**  288 2370 237 2658 522

### Energy **Efficient Tr**  **ansformers**

**To tal T**  **ransformer Losses v s Load** 

2000 2500 3000 

## EXAMPLE 

# 75kV **A Tr**  **ansformer**

**E fficiency** 

11 0 500 1000 1500

0 10 20 30 40 50 60 70 80 90 100 **Percent Load**  **Total Loss in Watts**  NEMA TP

- 1 Standard 150 Rise Standard 80 Rise

### Energy **Efficient Tr**  **ansformers**



## 96 **98 100** **E f** **f i** **c i** **e n** **c y** **( %** **)** 

## EXAMPLE 

# 75kV **A Tr**  **ansformer**

**E fficiency** 

12 

## 90

**92 94**  **96**

**10 20**  **30 40**  **50 60**  **70 80**  **90 100** 

**Percent Load E** **f f** **i c** **i e** **n c** **y (** **% )** 



## H
**- 150**  **H**
**- 80**  **TP1**

### Energy **Efficient Tr**  **ansformers**

2 3 4 5 6 7**B a** **c k** **P e** **r i** **o d** **( Y** **e a** **r s** **)** 

# 75kV **A Tr**  **ansformer**

**E fficiency** 

13 0 1 2

**Utility Rate ($)/KWH** **P a** **y -** **B a** **c k** **P e** **r i** **o d** **( Y** **e a** **r s** **) 0** **. 0** **3 0** **. 0** **3 5** **0 .** **0 4** **0 .** **0 4** **5 0** **. 0** **5 0** **. 0** **5 5** **0 .** **0 6** **0 .** **0 6** **5 0** **. 0** **7 0** **. 0** **7 5** **0 .** **0 8** **0 .** **0 8** **5 0** **. 0** **9 0** **. 0** **9 5** **0 .** **1 0** 

### Energy **Efficient Tr**  **ansformers** 

# Conclusion **on NEMA**

**T P** 
**- 1** 

• **TP**
**- 1**  **Tr ansformers ar**  **e** Good value

14 

# Good for the environment

They save ener gy

### Energy **Efficient Tr**  **ansformers** 

# Squar **e D NEMA**

**T P** 
**- 1**  **Tr ansformers ar**  **e Av**  **ailable Now** 



# • How Identified? Catalog Suf

fix “EE”

15 

# • How to Order Through Square D Distribution and/or Field Sales

• Vi sit Square D We bsite www .squared.com