in gen traf what is ONAN , ONAF , OFAF and DYN

Question Posted / anilnandyala

3 Answers
10447 Views
I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

in gen traf what is ONAN , ONAF , OFAF and DYN..

Answer / bimal ch b orah

onan means oil natural air natural
onaf means oil natural air forced
ofaf maens oil forced air forced
DYN primary is connected in delta and secondary is
connected in star

Is This Answer Correct ?

17 Yes

1 No

in gen traf what is ONAN , ONAF , OFAF and DYN..

Answer / pillay

Answers #1 & #2 is correct but i can add something for the the benefit of some.
In ONAN the oil in the TX former circulates on its own due to hot oil goes up & cooler oil goes down.The TX former is cooled by just the air around it.
In ONAF the oil circulates as above but a fan is used to cool it.
In OFAF the oil is pumped with a pump for circulation and the air is cooled by a fan.
In DYN the primary winding of the tx former is wound in delta and the secondary is wound in star with tapping for neutral connection.

Is This Answer Correct ?

10 Yes

0 No

in gen traf what is ONAN , ONAF , OFAF and DYN..

Answer / zahid

onan means oil natural air natural
onaf means oil natural air forced
ofaf maens oil forced air forced
DYN primary is connected in delta and seconday is connected
in star with neutral

Is This Answer Correct ?

8 Yes

2 No

Post New Answer

More Electrical Engineering Interview Questions

What is the difference between CRNO and CRGO in an transformer and what is the advantages of these two.

13 Answers Anchor, CIL, ETA, Kirloskar,

What kind of test is conducted commonly for generator? And explain briefly

1 Answers MAHINDRA,

What is gross error?

0 Answers

Why is the uniform distribution of the capacitor discs in a suspension type insulators essential , what can u do to improve the string efficiency ?

1 Answers

what is the formula to find Amp. for an 3 phase moter both if H.P. or if kW is known?

5 Answers Uttam,

In pakistan appliances work on 220v at 50hz and in us appliances work on 110v at 60hz what is basic theory to explain it

1 Answers SNGPL,

give information about REM5453 & SPAJ Relays

1 Answers

Explain the Term in CT Name Plate – Class: 5P10

6 Answers

What are the protections required in the main lt panel which is connected to the transformer.

1 Answers Ispat,

At site, we have 30Kw motor (3 phase, 400V,50Hz) and FLC 54A as per the nameplate. At the time of starting it draws 840A instead of 390A (7.2%). As per the data sheet also its 390A starting current. it thru a dol starter from the MCC. can anyone tell what is the problem in the motor

5 Answers ME,

Whet is IGBT.How it teste

2 Answers

what is the difference between effective earthing and resistive earthing?

3 Answers REL,

For more Electrical Engineering Interview Questions Click Here