This image is a follow up to an attempted repair of only tightening the center phase lug, despite a recommendation to replace the breaker. Between the time of the initial finding and the follow up, the temperature increased from 140 F to 176 F. The internal temperatures would be higher and moving the breaker closer to failure.
With years of experience and familiarity with electrical equipment we take pride in our ability to make recommendations for repair in our report findings. We find that most assume that all electrical problems are merely “loose connections”. We have learned that is often not the case and refer to our “hot spots” as “faulty” components.
The main cause of heating in electrical equipment is an increase in resistance to the electrical current flow. At first glance of the thermal image below it is easy to assume that with merely tightening the lug connection that the heating will go away. Closer examination clearly shows that the source of the heating is not at the lug but coming from inside of the circuit breaker.