Saving money with energy efficient motors

When you use electric motors in your business you can save energy through:

• good 'housekeeping' and correct usage
• proper maintenance
• correct motor sizing and system optimisation

Electric motor usage and housekeeping

Running motors when they are not needed wastes energy and can shorten equipment life. Even a relatively small continuous load can add up - the Carbon Trust notes that leaving 11kW of motors running over weekends could cost over £4,000 a year.

Improve day-to-day operation by:

• switching off motors when the process is idle, including out of hours
• keeping motors and drives in well ventilated areas so they can cool properly
• keeping motors and cooling fins clean so heat can dissipate

Electric motor maintenance

Motor maintenance is one of the most important ways of ensuring that your motors continue to work efficiently.

There are two types of maintenance - planned preventative maintenance (PPM) and breakdown maintenance. PPM is essential for the long-term reliability and energy efficiency of your critical motor systems.

Electric motor sizing and optimising

Lightly-loaded motors are less efficient than fully-loaded ones, so it is much better that they are loaded as near to their full capacity as possible. There are different ways that you can achieve this, including:

• replacing larger, partially-loaded motors with smaller, fully-loaded ones - see replacing motors to save energy
• optimising a system or process so that the motor is running at full capacity for shorter time periods instead of running continually with a partial load

If it's not practical to change your existing motors or optimise existing systems you can still make energy savings on motors running with very light loads by:

• fitting motor optimisers that reduce the average voltage and current
• running the motor continually using a different connection mode - for example, star/delta, which reduces starting current and starting torque