The Cutler-Hammer BR340ST 3 Pole Circuit Breaker offers protection to electrical devices with its long and instantaneous action. It makes use of electro-magnetic mechanism to safeguard electrical appliances against overcurrent and overload conditions. The BR340ST features a shunt trip that can be activated remotely for extra protection of the wiring and devices. The installation of this circuit breaker is made easy with a plug-on mounting which allows it to be attached to any surface. It has voltage current and interrupting ratings of 120/240 VAC 40 Amp and 10 kAIC. This circuit breaker is made for use in 3 phase systems.