When a commutator comes in for a repair , units are disassembled and rebuilt with new copper and mica segments using the same quality assurance processes applied to new commutators. Our engineers conduct failure analysis and then disassemble the unit inspecting each component. One of the most frustrating problems encountered by pre-war train operators, specific to motor repair , is an exploded commutator.
The problem arises when the fiber washer holding the commutator assembly together fails due to age. The sudden fragmentation of the three segments can create quite a spectacular motor failure. Turning and undercutting of electric motor commutators are performed for various reasons, but most notably for preventative maintenance.
For example: these services promote the uniform wear of motor or generator carbon brushes, which will extend the brush life. When we refurbish or repair a DC machine, the commutator will be skimmed and undercut to return it to its original condition ready to lay down a new film or patina in service. We fit new brushes, which are carefully bed-in with new tension springs if needed or required.
Do not over-lubricate. What is the purpose of the commutator in a motor?


