Maintenance goals

SERVICE AND MAINTENANCE TIPS Commissioning motors for optimum performance

Careful installation of motors will help ensure their efficient and reliable operation, minimising the potential for costly downtime or sub-standard operation. It is therefore essential that particular care is taken when installing and starting motors that have been in storage, or that have been subject to an off-site repair

Here, Karl Metcalfe, Technical Support at the Association of Electrical and Mechanical Trades (AEMT), (pictured) outlines the key steps that should be undertaken when commissioning motors.

A motor that has been in storage should first be cleaned to bring it back to the condition it was in when placed in storage. If there are any signs of damage, such as broken cooling fins, they should be investigated to assess whether any internal damage could have occurred and, where necessary, the damage should be repaired.

In an ideal scenario, motors should be stored in a vibrationfree environment. However, this is not always practical. If the motor under inspection may have been subject to vibration, there is a potential for the bearings to have been damaged. Even minimal ambient vibration will cause motor bearings to wear over time and can result in fretting or false brinelling, which can lead to motor failure. Therefore, unless there is complete certainty that the stored motor was not subjected to any vibration, the bearings should be inspected for signs of wear and replaced if necessary.

Bearing lubrication should also be considered when taking a motor from storage. Where the motor uses sealed bearings – and if it has been in storage for an extended period of two years or more – it is highly likely that the grease inside the bearing will have separated and will not work optimally. If the date when the bearing was fitted is unknown, or the motor has been in storage for a long time, then it would be advisable to replace the bearing.