220-66-kv-xmer-on-line-nifes-r4-sept-08 - Gujarat Electricity Board

GETCO/E/TS – XMER01power/R4 Sept 08
SECTION – II
TECHNICAL SPECIFICATION
FOR <strong>220</strong> kV CLASS POWER TRANSFORMERS
SPECIFIC REQUIREMENTS
2.1 SCOPE:
2.1.1 This section covers the specific technical requirements, climatic and isoceranic
conditions and system particulars for which the power transformer shall be offered
as per the general technical requirements given in Section – I of this specification
and the Schedule of requirements specified herein for the various sub-stations.
2.2 CLIMATIC AND ISOCERANIC CONDITIONS:
2.2.1 The climatic conditions under which the equipments shall operate satisfactorily.
(a) Maximum ambient temperature of air in Shade ( O C) 50
(b) Minimum ambient temperature of air in shade. ( O C) 50
(c) Maximum daily average ambient temperature ( O C) 40
(d) Maximum yearly average ambient temperature ( O C) 30
(e) Maximum relative humidity (%) 95
(f) Average number of thunder storm (days/annum). 15
(g) Average number rain fail (cm) 150
(h) Maximum wind pressure (kg / m 2 ) 150
(i) Height above monsoon level (mtr) Not exceeding
1000
2.2.2 All equipments offered shall be suitable for continuous satisfactory operation at the
full rated capacity under the climatic conditions.
2.2.3 Since the sub-station may be near seashore or industrial area, the equipment offered
shall be suitable for heavily polluted atmosphere.
2.3 TYPE AND RATING:
2.3.1 The transformers shall be either core or shell type construction, 3 phase, oil
immersed, ONAN/ONAF/OFAF with external heat exchanger and shall be suitable
for outdoor services. The rating and the electrical characteristics of the transformers
shall be as under:
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