Transformer Cooling Method at 12MVA

howmany types of cooling methods you know actually? you can ask any type for manufacturer. or they will suggest according to their product specification.

Normally there are 3 types as follows.

1 ONAN

2. ONAF

3. ONWF

4. OFWF

But if there are more than one MVA rating for the same transformer, then there can be stages of cooling like ONAN/ONAF etc.

Do u have any comments?

sks

There is some discussion about the selection of transformer cooling method (ONAN or ONAF) and transformer ratings in the previous thread http://cr4.globalspec.com/thread/43826. You can look into it for further help.

- MS

Hi,

How do you synchronize your generator to grid? Do you use a autosynchronizer?

actualy i only have knowledge about synchronizing genreators in paralle, i.e. lamp bright synchronizing.

i think, for a unit connected scheme, where a hydrogenerator is connected with transformer, and only then connected to circuit breaker to bus. Here, the cb is also called synchronizng breaker, because it connects generator part to load part i.e. bus part. We also have autosynchronizer, but how we do it manually - taking care of voltage, phase, phase sequence and frequency?

regards,

hi

It is mentioned on Transformer Name plate. If not mentioned better to ask manufacturer.

Generally 12 MVA generator transformers ONAN or ONAF.

ONAN - Oil natural air natural - This is like natural air cooling

ONAF - Oil natural forced air - In this condition fans are connected to transformer radiators and operating according to set temperature.

I hope this helps to you.

Regards

Hanu

Hi.

Looks like OFWF could be loaded to 167% to that of ONAN/ONAF of same rating.

sks