These types of cable reeling drums are normally used for cables of size 4C X 25 sq mm (max) and cable lengths upto 20 mtrs. However these drums can be used even upto 150 mtrs if the cable diameter is small (say 4C X 2.5 sq. mm ). In case of stall torque motorized cable reeling drum the stall torque motor remains energized in both winding and unwinding operation of cable. In case you want to save power during long stoppages of machine, then a contactor and timer circuit can be installed in your panel. However, this is only an optional feature and is not a mandatory requirement. Since the stall torque motors are continuously on during both winding and unwinding direction.