How to Specify a Motor

We are aware that some people who are using this website are unfamiliar with electric motors. This page is designed to give a bit of assistance in order to check what you require. The following details are for standard AC motors, if the motor you require is a DC motor, please ring us for a price etc.

  1. If replacing a motor, firstly look for the nameplate on the existing motor that you need to replace. If there is no nameplate, you may have to ring us with details of the machine it is being used on.
  2. Identify if the motor is single or three phase – this should be detailed on the nameplate with the voltage supplied to the motor.
  3. Identify the power rating or kilowatt kW reading. If the power is given in horsepower (hp), multiply by 0.75 to give the power in kilowatts.
  4. Identify the motor speed – this should be given in revs per minute (rpm) and will typically follow the following for a 50Hz motor:
    4a. rpm between 2800 and 3000 – 2 pole motor
    4b. rpm between 1350 and 1500 – 4 pole motor
    4c. rpm between 850 and 1000 – 6 pole motor
  5. Identify the mounting you require, this is typically: foot mounted (referred to as ‘B3’), flange mounted (B5) or face mounted (B14).

Mounting Options

  1. Select the efficiency level you require. This is designated by the IE rating. The higher the number (typically either 2 or 3), the more efficient the motor. Please note that, by law, IE2 motors can only be bought if being used with a drive/inverter.
  2. This should be enough information to specify the standard motor you require, but it is also advisable to check the frame references match and any other data on the nameplate. Remember if you are in any doubt whatsoever please call us on 0800 999 0200 – we are here to help and the number is free to call!

If you have any questions, call us on 0800 999 0200!