ActronAir Circuit Breaker MCB 2 Pole 40A 6kA C Curve provides overcurrent and short-circuit protection for ActronAir indoor and outdoor unit circuits, rated at 40A with 6kA breaking capacity and a C-curve trip characteristic suited to AC motor and transformer loads. The 2-pole 40A C-curve MCB trips faster than a B-curve breaker on motor starting transients but slower than a D-curve, providing the correct balance of nuisance-trip avoidance and fault protection for ActronAir unit circuits. Isolate power at mains before replacing any circuit protection components.