Images from a transformer station

The following images are examples, showing marginal heating, caused by a not ideal contact.

It is easy to detect even contacts with a small temperature rise (contact temperature is only about 20C). But we should keep in mind, that the used load power was only about 20%, so that the resulting temperature would be much higher with a higher load.

The warmer contact (a) should be compared with the corresponding areas of the other 2 phases (A or B). Point A or B shows no local hot-spot. It is very easy to detect the source of the heating.

Thermography allows the maintenance department to detect defects at an early stage and to change the component in a planned manner without pressure.