The three-phase induction motor drags its rotor with a rotating magnetic field and is the most widely used motor type in industry. As you move into the high-kW range, the mechanical strength of the frame becomes decisive; here a cast iron frame manages vibration and heat better than aluminium. DRG Motor supplies cast iron induction motors for high-power applications, giving a durable answer to demanding loads.

The Role of the Cast Iron Frame

A cast iron frame damps vibration thanks to its mass and spreads the motor's heat across a wider outer surface. On lines that run under shock loads such as conveyors, crushers and large pumps, this rigidity protects bearing life and shaft alignment. Aluminium is lighter, but in heavy-duty conditions the mechanical edge of cast iron is the reason to choose it.

Speed and Torque in the High-kW Class

On a 50 Hz supply, synchronous speed is set by pole count: 2-pole 3000 rpm, 4-pole 1500 rpm, 6-pole 1000 rpm. High-power applications usually favour 4- and 6-pole motors, because they produce more torque at lower speed and make heavy machines easier to start.

Protection, Insulation and Continuous Duty

Industrial induction motors are protected against dust and splashing water at IP55 and withstand high temperatures with Class F insulation. The S1 continuous duty rating means the motor can run for hours at full load without a break; the cast iron frame safely sheds the heat generated in this regime.

Choosing the Right High-Power Motor

DRG Motor supplies three-phase cast iron induction motors from 0.55 to 355 kW at 400 V / 50 Hz with B3 foot, B5 flange and B14 face mounting. Once your load profile, speed and mounting are clear, we can settle on the right combination of frame and power for heavy service together.