What is ONAN/ONAF1/ONAF2 for transformer cooling
Answers were Sorted based on User's Feedback
Answer / p.aruna devi
ONAN -Oil natural air natural
ONAF-Oil natural air force
| Is This Answer Correct ? | 228 Yes | 13 No |
Answer / gowhar
The above answer is true.Moreover ,there is a two stage
forced cooling in some of the transformer
(ONAN/ONAF1/ONAF2.on First stage forced cooling(ONAF1) the
MVA rating increses 33% of the actual rating and on second
stage cooling(ONAF1) MVA rating increases to 66% of the
actual rating.
| Is This Answer Correct ? | 98 Yes | 34 No |
Answer / shashank
ONAN type cooling:
The generated heat can be dissipated in many ways. In case
of smaller rating of transformers, its tanks may be able to
dissipate the heat directly to theatmospheric dry while
bigger ratings may require additional dissipating surface
in form of tubes/ radiators connected to tank or in the
term of radiator tank. In these cases, the heatdissipation
is form transformer oil at atmospheric air by natural
means. This form of cooling is known as ONAN (Oil Natural,
Air Natural) types of cooling.
ONAF type of cooling:
For further augmenting the rate of dissipating of heat,
other means such as fans blowing air on the cooling
surfaces are employed. The forced air takesaway the heat at
a faster rate, thereby giving better cooling rate than
natural air. This type8
of cooling called ONAF (Oil Natural Air Forced) type of
cooling. In this coolingarrangement, additional raring
under ONAN condition viz. after shutting off fans,
isavailable, which is of the order of 70-75%.
| Is This Answer Correct ? | 41 Yes | 2 No |
Answer / abdullah ibrahim
The generated heat can be dissipated in many ways. In case
of smaller rating of transformers
| Is This Answer Correct ? | 10 Yes | 0 No |
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