If the transformer runs hot for extended periods of time, then it will degrade the winding insulation varnish and eventually burn up. Transformers when properly loaded will only run at a warm to the touch temperature, not hot to the touch temperature.

Knowing how to calculate the full load ampacity of a transformer is a very important calculation to have in your bag of tricks as a hvac service technician. Here you will see how to calculate the transformer full load amps. The full load ampacity describes how many amps the transformer is designed to handle.

This is important because it helps determine what size transformer is needed to hand a particular load and keeps the transformer from running hot, which will cause the transformer to burn up.