IEEE C57.12.00-2010 pdf free.IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers.
IEEE C57.12.00 describes electrical and mechanical requirements of liquid -immersed distribution and power transformers, and autotransformers and regulating transformers, single-phase and polyphase, with voltages of 601 V or higher in the highest voltage winding. This standard applies to all liquid-immersed distribution, power, and regulating transformers that do not
belong to the following types of apparatus:
a) Instrument transformers
b) Step voltage and induction voltage regulators
c) Are furnace transformers
d) Rectifier transformers
e) Specialty transformers
f) Grounding transformers
1.2 Purpose
This standard is a basis for the establishment of performance, and limited electrical and mechanical interchangeability requirements of the equipment are described. It is also a basis for assistance in the proper selection of such equipment.
1.3 Word usage
When this standard is used on a mandatory basis, the words .chull and must indicate mandatory requirements. The words shiu!d and mat refer to matters tha are recommended or permissible. but not mandatory. Thc introduction of this voluntary consensus standard dcscribcs the circumstances under which the standard mat be used on a mandatory basis,
2. Normative references
The following referenced documents are indispensable for the application of this document (i.e., they must be understood and used, so each referenced document is cited in text and its relationship to this document is explained). For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments or corrigenda) applies.
3. Definitions
Standard transformer terminology available in IEEE Std C57.12.80 shall apply.” The IEEE Standards Dictionary: Glossary of Terms & Definitions should be referenced for other clectrical terms.
4. Service conditions
4.1 Usual service conditions
4.1.1 General
Transformers conforming to this standard shall be suitable for operation at rated kVA under the following usual service conditions.
4.1.2 Temperature Cooling air temperature limit
When air-cooled, the temperature of the cooling air (ambient temperature) shall not exceed 40 °C, and the average temperature of the cooling air for any 24 h period shall not exceed 30°C. Liquid temperature limit
The top liquid temperature of the transfonncr (when operating) shall not be lower than —20 °C. Liquid temperatures below —20 °C are not considered as usual service conditions. Cooling water temperature limit
When water-cooled, the temperature of the cooling water (ambient temperature) shall not exceed 30 °C. and the average temperature of the cooling waler for any 24 h period shall not exceed 25 ‘C. Minimum water temperature shall not be lower than I °C. unless the cooling water includes antifreeze, which is suitable for -20 °C operation.
4.1.3 Altitude
The altitude shall not exceed 1000 m (3300 fl).
4.1.4 Supply voltage
The supply-voltage wave shape shall be approximately sinusoidal, The phase voltages supplying a polyphase transformer shall be approximately equal in magnitude and time displacement.
4.1.5 Load current
The load current shall be approximately sinusoidal. The harmonic factor shall not exceed 0.05 per unit. Harmonic factor is dcflncd in IEEE Std C57. 12.80.IEEE C57.12.00 pdf free download.