What is Rewinding an Electric Motor and Why Your Motor May Need Rewinding

Rewinding of an industrial electric motor can often be a cost-effective solution. When an electric motor suffers damage to or failure of a motor’s insulation due to heat, over work or age, there is no need to necessarily replace it with a new motor, which can at times incur additional costs and possible long lead times. Motor rewinding can get the motor back in good working order without the higher cost of possibly purchasing a new one.

Electric motor rewinding involves three basic steps: removal or stripping of the winding (coils), Inserting and connecting new winding (coils), and insulating the complete winding. This can be complex process.

There can be a wide variety of issues resulting in motor failures that necessitate rewinding and can normally be found in any or a combination of these forms failed insulation, grounded coils, shorted coils, and Thermal deterioration.

Insulation failures issues can usually be traced back to contamination, abrasion, voltage surges, overall age, or vibration.

Thermal deterioration is caused when the insulation overheats due to poor connections in the motor terminal, a locked rotor resulting in high currents in the stator, excessive load demands that exceed the motor’s rating, or excessive reversals and starts.

What is a dip and bake?

Dip and Bake is a process that can be used as a standalone refurbishment for an electric motor if there is no damage to the windings and will also be done to protect the windings of a new rewind. Dip and Bake is a standard varnishing technique where the motor windings are dipped into a varnish tank and then set to cure in an oven. Typically, a new motor winding should be dipped twice (double dip and bake) to ensure the varnish fully covers the windings.