Description

Type 4013 counter torque hoist controller is recommended for applications such as bucket hoists, boom hoists and magnet cranes, where a fixed minimum load exists which insures an overhauling condition at all times and where accurate positioning and slow steady speeds are not required.

The Counter Torque system uses reverse power to control speed in the lowering direction without the need for a load brake.

Control in the hoisting direction is the standard secondary resistor method with frequency responsive type acceleration.  In the lowering direction, the master switch is no effective until the third point.  If the load is heavy enough, it will begin to lower.  If the load is not heavy enough, it will try to hoist, but a frequency sensing relay will prevent hoisting.  The operator does not have to reset the control by returning the master switch to the off point.  Moving the master switch to the fifth-point lower will accelerate the motor to full speed under control of the frequency responsive accelerating relays and drive the load down in regeneration.  The operation in fourth-point lowering is the same as described for the third point, except the load accelerates to a faster speed.