Do any performance issues arise during high ambient temperatures?

Temperatures which exceed the rated ambient temperatures for which the insulation system is designed can cause insulation damage and premature failure. This can often occur in hotter
environments or in rooms which have inadequate ventilation. Care should be taken in installing stacked transformers because the top transformer may use air that has been heated by the lower unit. Damage from high ambient temperatures often does not cause an immediate failure but can cause damage that results in a failure weeks, months or years later.

High ambient temperatures can be mitigated several ways:

  • Order a transformer designed with a lower temperature rise.
  • Use fan cooling, this is typically an economical solution when a unit exceeds 500-1500kVA.
  • Place the transformer in a temperature controlled location.
  • Properly ventilate the location that the transformer is located in.

Never try to use cooling fans directly on a transformer or blow across a transformer’s windings.

Manufacturers use special fans, specific locations, and cooling patterns to cool transformers. Improper placement of airflow could cause disruption of the convection airflow and cause the transformer to overheat.