Electric MCB

40A Ellgee Double-pole breakers have two hot wires that are connected by a single neutral wire. That means if there's a short circuit on either of the poles' hot wires, both trip. These breakers can be used to serve two separate 120-volt circuits or they can serve a single 240-volt circuit, such as your central AC's circuit.

An MCB is an automatically operated electrical switch. Miniature circuit breakers are intended to prevent damage to an electrical circuit as a result of excess current. They are designed to trip during an overload or short circuit to protect against electrical faults and equipment failure.