High-efficiency transformers make financial benefits for the society. Other than diminished greenhouse gas emanations, they progress reliability and deliver possibly longer benefit life by bringing down temperature rises through energy-efficiency advancements. India has, by presently, received the universal IEC standards as well as presented star naming for chosen categories of transformers. Most power losses happen within the transformer core made up of magnetic steel or within the electrical coils or windings of either aluminum or copper. Copper diminishes load loss, since it could be a more proficient conductor.
The significant Indian standard for distribution transformers (DTs) IS:1180/1989 has been changed within the year 2014 as IS:1180 (Part1)/2014 by Bureau of Indian Standard (BIS) subsequently superseding IS:1180 (Portion 1 and 2)/1989 both for fixed and non-sealed sort. This standard advance prescribes numerous reviewing with respect to vitality effectiveness, i.e. three energy-efficiency levels: level 1, level 2 and level 3 of transformers comparing to 3 star, 4 star and 5 star named transformers separately, as endorsed by BEE (moreover as per CEA required rules)



IS 1180 Energy Efficiency Level 2 Transformer Specification

PhaseThree Phase
Frequency50 Hz
Winding MaterialCopper/Aluminium
RatingsUpto 200 kVA
Primary voltageUpto 11000 V
Secondary Voltage433 V
Temperature Rise35 C / 40 C


Energy Efficient Transformer Technical Data

Star Rating Distribution Transformers with Energy efficiency level 2 as per IS 1180:2014 (Part I)

  • Maximum Ambient Temperature=45°C
  • Oil temperature Rise: 35°C
  • Winding Rise: 40°C
  • Tap switch: NIL(For 16 KVA to 100 KVA)
  • Type Of Winding Aluminum wound Off circuit Tap switch: +5% to -5% @ 2.5%(For 160 & 200 KVA)


Energy Efficiency Level 2 Transformer Toc Formula For Distribution Transformer..

  • TOC (Total Owning cost) = IC+ (A X Wi ) +(B X Wc)
  • IC = Initial cost (unit end cost without tax) of transformer as quoted by the bidder.
  • Wi  = No Load losses quoted by the bidder in Watt
    Wc  = Full load losses at 75 °C quoted by the bidder in Watt
  • A Factor = Cost of no load losses in Rs/ Watt
    B Factor = Cost of full load losses at 75 °C in Rs. / Watt
Energy Efficiency Level 2 Transformer Evaluation Criteria

Distribution Transformer in KVA

Level 1 rated Transformer

Level 2 rated Transformer

*Total loss in watts at 100 % loading should not be lower than
(Not equal to)

*Total loss in watts  at 100
%        loading should not be
higher than

*Total loss in watts at 100 % loading should not be lower than (Not equal to)

*Total loss in watts at 100
%      loading should not be
higher than

5

95

115

75

95

10

240

270

215

240

16

440

480

400

440

25

635

695

595

635

63

1140

1250

1050

1140

100

1650

1800

1500

1650

200

2300

2700

2100

2300

500

4300

4750

4100

4300

 

Is 1180 Energy Efficiency Level 2 Transformer Percentage Impedance

Rating of Transformer in KVA

Percentage Impedance at 750C

5 KVA

4.00 %

10 KVA to 100 KVA

4.50 %

200 KVA & 500 KVA

4.75%

 

Energy Efficiency Level 2 Transformer Temperature Rise

Temperature Rise

5 KVA

10 to 500 KVA

Top    oil    temperature
thermometer

rise

measured

by

30 deg.C

35 deg.C

Winding     temperature
resistance

rise

measured

by

35 deg.C

40 deg.C

 

Is 1180 Energy Efficiency Level 2 Transformer Routine Tests

  1. Measurement of winding resistance (at all taps if applicable) [IS2026 (Part1)].
  2. Measurement of voltage ratio, polarity, phase sequence and vector group[IS2026(Part1)].
  3. Measurement of short-circuit impedance (principal tapping, when applicable)
  4. Load losses at rated current and normal frequency,at50 % and100 % load [IS2026(Part1)].
  5. Measurement of no-load loss and current [IS2026(Part1)].
  6. Measurement of insulation resistance [IS2026(Part1)].
  7. Induced over-voltage withstand test[IS2026 (Part3)].
  8. Separate-source voltage withstand test [IS2026(Part3)].
  9. Pressure and vacuum test(as per IS: 1180-2014).
  10. Oil leakage test(as per IS: 1180-2014).
  11. Neutral current measurement, shall not be more than 2% of full load current (CEA Guideline 2008 clause no 34.9)
  12. Oil samples (one sample per lot) to comply with IS 1866.
  13. Measurement of no load losses and magnetizing current at rated frequency and at 90%, 100%and 112.5% voltage

 

Highlighted Points For Is 1180 (Part 1) : 2014

In revised IS specification, losses for each rating for each category have been defined in three levels which are denoted by as follows;

  • a) Energy Efficiency Level 1
  • b) Energy Efficiency Level 2
  • 3) Energy Efficiency Level 3

In each level maximum losses (No Load Loss + Load Loss) at 50% load & 100% load have been specified for each rating in all categories.

a) Three phase distribution transformers upto and including 200KVA, 11KV Class

Sl. No.
Rating (KVA)
% Z
Energy Efficiency Level 1
Energy Efficiency Level 2
@ 50%
@ 100%
@ 50%
@ 100%
1
16KVA
4.5%
150W
480W
135W
440W
2
25KVA
4.5%
210W
695W
190W
635W
3
63KVA
4.5%
380W
1250W
340W
1140W
4
100KVA
4.5%
520W
1800W
475W
1650W
5
160KVA
4.5%
770W
2200W
670W
1950W
6
200KVA
4.5%
890W
2700W
780W
2300W

 

b) Three phase distribution transformers Higher than 200KVA upto and including 2500KVA, 11KV Class

Sl. No.
Rating (KVA)
% Z
Energy Efficiency Level 1
Energy Efficiency Level 2
@ 50%
@ 100%
@ 50%
@ 100%
1
250KVA
4.5%
1050W
3150W
980W
2930W
2
315KVA
4.5%
1100W
3275W
1025W
3100W
3
400KVA
4.5%
1300W
3875W
1225W
3450W
4
500KVA
4.5%
1600W
4750W
1510W
4300W
5
630KVA
4.5%
2000W
5855W
1860W
5300W
6
1000KVA
5.0%
3000W
9000W
2790W
7700W
7
1250KVA
5.0%
3600W
10750W
3300W
9200W
8
1600KVA
6.25%
4500W
13500W
4200W
11800W
9
2000KVA
6.25%
5400W
17000W
5050W
15000W
10
2500KVA
6.25%
6500W
20000W
6150W
18500W

 

c) Single Phase distribution transformers upto and including 25KVA, 11KV Class

 

Sl. No.
Rating (KVA)
% Z
Energy Efficiency Level 1
Energy Efficiency Level 2
@ 50%
@ 100%
@ 50%
@ 100%
1
5KVA
4.0%
40W
115W
35W
95W
2
10KVA
4.0%
70W
190W
60W
170W
3
16KVA
4.0%
95W
265W
82W
224W
4
25KVA
4.0%
125W
340W
110W
300W


Further to above it is also observed that IS 1180 are now also applicable for 22KV & 33KV class transformers, losses values for 22KV & 33KV class transformers shall be applicable as per below clause:
  • a) For transformers having voltage class above 11KV and upto and including 22KV, the permissible total loss value shall not exceed by 5% of the maximum total losses values mentioned in table a) & b) for three phase.
  • b) For transformers having voltage class above 22KV and upto and including 33KV, the permissible total loss value shall not exceed by 7.5% of the maximum total losses values mentioned in table a) & b) for three phase.
  • c) For transformers having voltage class above 11KV and upto and including 22KV, the permissible total loss value shall not exceed by 7.5% of the maximum total losses values mentioned in table c) for single phase.
  • d) For transformers having voltage class above 22KV and upto and including 33KV, the permissible total loss value shall not exceed by 10% of the maximum total losses values mentioned in table c) for single phase.

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