How does an electric motor work?

It’s easy to take electric motors for granted, but our lives would be very different (and difficult!) without them. For example, an average car contains around 30 motors!

Electric motors have been used to power machinery for over 150 years. But how exactly do they work? Gibbons Group has 45 years’ experience in the manufacture and repair of electric motors and is on hand to explain all. In this instance we’ll be referring to AC (alternating current) electric motors.

• An AC electric motor is made up of two main components – the stator (stationary part) and the rotor (rotating part).
• A coil of wire is wound through the stator, creating one or more pairs of magnetic poles. To increase the magnetic flux, the coil has many turns.
• When the motor is switched on, electric current flows through the coil and the magnetic force causes the rotor to turn. This force is known as torque.
• The rotor continues turning as it passes between each set of magnetic poles.
• This continuous motion means a shaft, connected to the rotor, can then be attached to a machine and operate it.
• A motor may burn out when overheating causes the wire insulation to melt, at which point there are two options – to replace it or have it rewound.
• A motor rewind involves removing and replacing the old wire – a labour-intensive process requiring specialist skills. Gibbons started rewinding motors in 1969 and continue to offer the service today.
• Depending on the size of the motor, it may be cheaper to simply order a new one. However, the cost of replacing a large or specialist motor can be huge compared to the price of a rewind.

For more information on Gibbons’ range of ABB electric motors, please call 01621 868138, email paul.scott@gibbonsgroup.co.uk or visit our Electric Motors page.