Force Cooled D.C Motors
Motors used for variable speed drives, normally run in the speed range of 1:20 by armature control & are cooled by a separate force cooling unit mounted on the motor. Normally this unit consists of 1/3 Ph. A.C. motor driven Fan (blower), which runs at a constant speed, giving constant rate of cooling, irrespective of the speed of the main D.C. Motor.
