Cutler-Hammer FD3040U is a three-phase circuit breaker rated for 40 A at 600 V in a 3-pole (3P) configuration. The FD3040U designation identifies a 40-amp, 600-volt protective device from Cutler-Hammer used to interrupt current on three-phase feeders. In industrial and commercial electrical systems, it provides overcurrent protection for circuits and equipment operating on a 600-volt three-phase supply.
