Maintenance of Automatic Air Circuit Breakers

Automatic air circuit breakers are structurally more complex than contactors and magnetic starters because they have a relatively complete arc extinguishing device. They can automatically trip the circuit in the event of overload, short circuit, undervoltage, or voltage loss.

a. Closing and tripping test.
b. Adding lubricant to the transmission mechanism.
c. Phase-to-phase insulation resistance calibration.
d. Overcurrent calibration of the switch.
e. Inspection of incoming and outgoing contacts.
f. Inspection of the arc extinguishing grid.
g. Contact maintenance.