Question

State four (4) possible causes each of the following troubles in dc motor and suggest two
solutions to avert them:
(i) sparking at brushes, and (ii) overheating.

Answer 1

(i)

Causes:

1) Worn out brushes.

2) Vibration in the machine.

3) Brushes not in proper position.

4) Rough or burnt commutator.

Remedy:

1) Clean the commutator from time to time.

2) Check for the uneven wear out of the commutator.

(ii)

1) Load driven is very high (Overloading).

2) Ambient temperature is high.

3) Frequent starts and stops.

4) Fluctuations in input voltage.

Remedy:

1) Never overload the motor and keep it well maintained.

2) Try to put the motor in a ventilated chamber.