Overheating in ACB plays havoc in the degradation of the performance of the Air Circuit Breaker. Following are the factors that cause overheating in ACB with its preventional remedies.

Cause 1 : Poor Termination, Improper termination or improper use of instruments to tighten the screw of ACB. This causes the voltage drop due to loose contacts in ACB thus results overheating.

Preventational Remedy : (1) Proper use of an instrument to tighten the screw for termination. The termination nuts should be tightened with the proper torque which is done with the use of the proper wrench.
(2) Clean the terminals with proper solvents (CRC-2-26 & ) and do the termination.

Cause 2 : Dusty Ambiance inside ACB.

Preventional Remedy : Periodical cleaning of ACB period of cleaning within 3-4 months.

Cause 3 : Due to use of undersized power cable or busbars.
Preventational Remedy : Use of busbars and power cables of suitable rating.

Cause 4 : High atmospheric temperature.

Preventational Remedy : Reduction in load current and proper selection of the ACB.