7.5 kW 3000 RPM ELECTRIC MOTOR

CONTACT: +90 542 666 11 11

At 3000 RPM a 7.5 kW motor spends its life at twice the shaft speed of the common 1500 RPM build, and everything that matters about it follows from that. Rotor balance, bearing selection and the fan noise stop being secondary; they are the reason a high-speed machine is specified as a high-speed machine rather than as a 7.5 kW motor that happens to be fast.

The two-pole build gives about 10 HP at the shaft and is chosen where the driven machine wants speed rather than torque: centrifugal pump sets, blowers and radial fans, screw and piston compressors, machine-tool spindles. Belting it down from 3000 RPM to feed a slow load is the one thing this motor should not be asked to do.

Housing choice at high speed:

  • Aluminium – lighter, cooler, easier to align on a skid

  • Cast iron – heavier, damps vibration, preferred on compressor frames

IP55 is standard and IP65 is available. At 3000 RPM the more important line is that the fan path stays clear, because a blocked cover raises the winding temperature faster on a high-speed machine than on a slow one.

What High Speed Demands Internally:

  • Pure copper windings, sized for the current the duty actually draws

  • Class F insulation, with headroom for the warmer running of a fast machine

  • Dynamically balanced rotor — balance grade is what sets vibration at 3000 RPM

  • Sealed bearings selected for high speed, greased for long intervals

The motor is supplied in IE2 with IE3 available on request. On a compressor or a booster set running most of the day the higher class is worth ordering, because a two-pole machine on continuous duty accumulates hours quickly.

Mounting and Coupling at 3000 RPM

  • B3 (foot-mounted) — bolted to a base plate or slide rail

  • B5 (flange-mounted) — straight onto the pump or blower casing

  • B14 (small flange) — where the machine envelope is tight

Alignment tolerance is what separates a high-speed installation from an ordinary one: a coupling that passes at 1500 RPM can shorten bearing life at 3000 RPM. Shaft diameter, flange dimensions and terminal box position are made to the machine, and the motor runs on an inverter where the process wants the speed trimmed rather than throttled.

Options Worth Ordering With It:

  • PTC thermistors or PT100 sensors — winding temperature on a fast machine

  • Encoders — where speed or position is read back to the control

  • Electromagnetic brakes — where the load must be held after stopping

  • Automatic lubrication — where the bearings are hard to reach in service

Servicing follows the speed: grease intervals are shorter than on a 1500 RPM machine of the same rating, and a vibration reading taken at commissioning gives the reference that every later reading is judged against.

On a pump or a fan, speed and power are not proportional — trimming the speed a little takes a disproportionate amount off the power drawn, which is why a 7.5 kW two-pole set on an inverter usually saves more than the same motor throttled at the valve.

Tell us the driven machine, the duty and the mounting, and we confirm whether the 3000 RPM or the 1500 RPM build fits it. You can order this motor and the rest of the range from DRG Motor. CONTACT: +90 542 666 11 11