ICS 29.180                         ETD 16

New Standard from Last Update.

1 SCOPE

This standard specifies the requirements and tests including standard loss levels of natural/synthetic organic ester liquid immersed, natural air-cooled, outdoor/indoor type, double-wound distribution transformers for use in power distribution systems with nominal system voltages up to and including 33 kV and of following types and ratings:

a) Three phase ratings up to and including 200 kVA both non-sealed and sealed type;

b) Three phase ratings higher than 200 kVA, up to and including 2 500 kVA both non-sealed type and sealed type; and

c) Single phase ratings up to and including 100 kVA sealed type.

This standard permits use of natural esters as well as synthetic organic esters in both non-sealed and sealed type of transformers. However, in case of non-sealed type transformers immersed in natural ester, suitable liquid preservation system such as airbags shall be used in the conservator to prevent direct contact of natural ester with the atmosphere.

NOTES

1 The following types of transformers are not covered under the scope of this standard:

a) Inverter duty transformers;

b) Traction transformers;

c) Instrument transformers;

d) Transformers for static converters;

e) Starting transformers;

f) Testing transformers;

g) Welding transformers;

h) Earthing transformers;

j) Mining transformers;

k) Transformers for solar, wind power application;

m) Transformers for railways (locomotive and other applications);

n) Furnace transformers;

p) Rectifier transformers;

q) Dual ratio in primary/secondary windings transformers; and

r) Transformers for Static VAR compensator.

2 Forindoor type distribution transformers, relevant provisions of Central Electricity Authority (CEA) Regulations, if any, shall be applicable.

2 REFERENCES

The standards listed in Annex A contain provisions which, through reference in this text, constitute provisions of this standard. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards listed in Annex A.

Annex B gives a list of IEC standards, IEEE standards, CIGRE brochures etc. available on ester liquids.