- Defective brush holder,
- Worn out carbon brushes,
- Uneven condition of commutator.
- Defective armature winding
20 April 2011
Commutator is an essential part of a DC Motor. DC Supply to the Armature of a DC Motor is fed through Carbon Brushes and Commutator. The most common fault observed in DC Motor is sparking of Commutator. The below video shows sparking from a commutator.
The common reason for spark from commutator is improper brush contact. This can be due to
The sparking create pitting of commutator and as we operate the motor spark will increase and will seriously damage commutator. Spark will make carbon brush burn and it will worn out very fast. The below picture shown damage to the commutator of above motor. Here the segments are worn out at particular (at the place of carbon brushes) part of commutator. That create sparking. It can be rectified by polishing the commutator. Every time after polishing the commutator it should be ensured that proper undercut is given to the mica between the segments.