What are the reasons for abnormal sound or noise?

1 Answer

Answer :

Motors in general should run very quietly and no abnormal noise is desired.

However if noise is there, it could be because of following reasons.

a. Windage noise – the noise due to ventilating system, (whistling noise).

b. Bearing noise – the noise due to its rolling contact.

c. Unusual noise – some defects inside the motor (example – motor bar failure).

d. Deep heavy growling noises – some electrical fault.

For permissible limits of noise levels for rotating electrical machines IS: 12065:1987

is being reffered. 

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