GTM1L series earth leakage circuit breakers are mainly applied to AC 50Hz, rated
voltage 400V and below, rated current up to 630A, they can be indirectly used for
protecting from electric shock, or to prevent against the fire danger result from
the earth fault due the damaged insulating of the equipment, and used to distribute
electric energy and protect the circuit and power source equipment from
overload, short circuit.

And it also can be used for switching the circuit and starting the motor infrequently.
The breaker can work normally when one of the three-phase poles default the
power.