Noisy Contactor

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In addition to the already mentioned particular matter, depending on the connected load, frequency of starts, rating and sizing of the starter, etc. could be inrush current from connected load or motor for example. Have you checked the inrush and voltage drop in % rating +\- for the connected load and panel loading on the line side?


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EEC said:
A 3 phase contactor was real noisy when first pulled closed, then after about 20 seconds sounded normal. What do you believe the cause could be?
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Jraef said:
In my experience even flattened swarf still makes the contactor noisy.

Bottom line though is still that the contactor needs a good cleaning, done safely.
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Besoeker said:
Or even just replacing.
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The decision to either clean or replace the contactor is usually based on the size and cost of the replacement.

It's good training if the electrician is not overly familiar with contactors and motor starters for them to take apart and clean up a contactor or starter so to better understand the inner workings.

If they have compressed air I would try just blowing out the foreign matter to start with. I have worked in areas where this is a common occurance because of all the lint and dust in the air and it would have gotten expensive to replace contactors and starters because of a little lint.
 
growler said:
The decision to either clean or replace the contactor is usually based on the size and cost of the replacement.

It's good training if the electrician is not overly familiar with contactors and motor starters for them to take apart and clean up a contactor or starter so to better understand the inner workings.

If they have compressed air I would try just blowing out the foreign matter to start with. I have worked in areas where this is a common occurance because of all the lint and dust in the air and it would have gotten expensive to replace contactors and starters because of a little lint.
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That and if you brush any rust off the magnet parts and put a little oil or silicone spray on them they do quiet down most of the time. A broken or loose shading coil is a problem that usually can't be repaired well enough though.
 
growler said:
The decision to either clean or replace the contactor is usually based on the size and cost of the replacement.
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Yes, I agree with that. And we don't know what size contactor the OP had. But up to about 37kW here replacement would be cheaper that spending time dismantling.

growler said:
It's good training if the electrician is not overly familiar with contactors and motor starters for them to take apart and clean up a contactor or starter so to better understand the inner workings.
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Not what I would suggest in a production plant like a paper mill where down time can be more that $10,000 an hour.
Sure, if the offending item can be taken out of service and played with on the bench. Even then, economics may come into play.

growler said:
If they have compressed air I would try just blowing out the foreign matter to start with. I have worked in areas where this is a common occurance because of all the lint and dust in the air and it would have gotten expensive to replace contactors and starters because of a little lint.
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Moisture may be a problem with that.
 
Electric-Light said:
Think twice about this. The stuff is not air. Read the can and it tells you not to use it to clean shredder because of the gas getting set off by the sparks in the brush or switch. Certainly not something to use near heavy duty contactor. The stuff is flammable and you can easily prove it yourself.
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Yeah! Pretty sure I'm NOT gonna pull the coil on an energized contactor!
 
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