Location of Dry Type Transformer

[rajendrarohra1978]

We have a dry type transformer 225 KVA,480/220/127 Vwhich is installed in shade, which is open from all sides, we need to replace the shade with closed room. The transformer is vented type ( with openings for air circulation). If we make closed room with split AC installed in that room, would that be ok or is it required to make vents in closed room for natural air circulation. how much ventilation space is required in that case.

Best regards,

 

[dpc]

You need to estimate the heat rejected by the transformer, then determine the ventilation and cooling requirements. The transformer rating is based on an average ambient temperature of 30 deg C. Transformer efficiency will be at least 95%, being very conservative.

 

[prc]

There is no need for providing air conditioners inside the cubicle. Provide at least 1 metre clearance from transformer outer surface all around the cubicle and provide bottom air inlet and top exhaust vents in the room. Exhaust normally 10 % more area than inlet.Limit the inside air max 30 C at full load.Some cases it may be necessary to provide an exhaust fan. For the theory and typical calculations refer to ABB Switchgear Manual (old BBC Manual) Clause 4.4.2 in 12th edition of 2012 -Ventilation of Transformer Rooms.