Adding capacitor to reduce contactor humming

[Elbow]

Hi,

As everybody probably knows, my grid voltage sags quite low when my house is drawing heavy.

I have a contactor installed with the coil powered from the grid.  This contactor hums or buzzes to some extent all the time but gets noisier when the voltage drops.

Can I do anything to reduce the buzz?  I wondered about using a capacitor as a high pass filter.

[Gerrie]

I personally don’t know of a solution with a capacitor.

1. Normally a contactor hum due to dirt inside on steel core face. You can try and clean it but it might already be too late.

2. Low voltage will also cause humming, but this will eventually cause contactor failure. The humming will gradually grind away further into the face and you will probably notice some fine dust inside when opening the unit.

You could try getting a slightly lower rated voltage coil which is relatively cheap but than you might have a problem again with over voltage when grid supply is high.