How to determine fan and motor for cooling system of tansformer.

[dheXjhe]

In the Design of Transfomer have ONAN system, if we want to change being ONAF, what the rating of fan to be increase the rating up to 15 %. How to determine that? Please Help me..

 

[rbulsara]

You can either do extensive heat transfer calculations or speak to the transformer manufacturers. Most manufacturers will have a kit for it. Hopefully the existing transformer has winding temperature sensors already or has the wells for them, a must for the fan control/transformer protection system.

Rafiq Bulsara

http://www.srengineersct.com

 

[burnt2x]

You need to know the ff:
Volume of oil in the tank and cooling equipment, ambient air temp, cooling surface area, transformer winding insulation type, winding temperature indicator/s, winding hotspot temperature calculation, top-oil temperature rise over ambient temperature at rated load, bottom-oil temperature rise over ambient temperature at rated load, load losses at rated load, no-load (core) loss, winding resistances, etc.
And then do what Rafiq said for a start.

 

[prc]

As bulsara said, go to any transformer manufacturer and get a kit from him.

There are two ways of putting cooling fans on radiator fins.From bottom of stack or side mounted.Size of propellar fans may be 18,24 or 36 inches-can be single phase or three phase.There is an optimum air flow above which there is no advantage in increasing air flow rate.

 

[dheXjhe]

ok, thank you for your advise all. i will try to ask this case with manufacturer.