Electricity Knowledge Sharing: Dry-type transformer cooling method

Dry-type transformer cooling methods are divided into natural air cooling (AN) and forced air cooling (AF).

In natural air cooling (AN), under normal use conditions, the transformer can operate continuously for a long

time under the rated capacity. When forced air cooling (AF), the output capacity of the transformer can be

increased by 50% under normal use conditions, which is suitable for intermittent overload operation or

emergency accident overload operation; due to the large increase in load loss and impedance voltage

during overload, It is not economical operation state, so it should not be kept in continuous overload operation

for a long time.

For both natural air cooling (AN) and forced air cooling (AF) transformers, it is necessary to ensure that

the transformer room has a good ventilation capacity. When the transformer is installed in a basement or

an environment with poor ventilation capacity, a heat dissipation and ventilation device must be added.

The ventilation volume can be selected according to the air volume required for each 1kW loss (PO+PK)

of 2~4m3/min.

The new curtain fan air cooling system has reduced noise, uniform cooling, and good effect; small size,

small footprint, and no more than the outline size of the transformer body; small fan capacity, distribution

transformer fan below 2500kVA is only 180W~540W, and adopts Single-phase AC220V power supply.

But it should be noted that this power supply should be taken from the circuit breaker in the low-voltage

MCC or PC distribution panel, not directly from the low-voltage outlet busbar of the transformer.