For use with ac wound rotor motors on crane hoists without mechanical load brakes but with fixed overhauling loads such as bucket crane hoists. Controllers are arranged for use with rectifier operated DC shunt brakes or solenoid operated ac brakes
Provides slow lowering speeds for overhauling loads only Mill Duty Class 8503 Type Clapper type contactors
Class 8501 Type SZF Type SZF Frequency Acceleration Relays