Contact Cleaner Deoxit D3?

[powerplay]

Hello,

I've had issues with noisy 3 pole 120 volt coil 600 volt ABB Definite Purpose Contactors. When I shut off the power to the Coil and turn back on, it seems an noisy contactor may be quiet and another turns noisy. What could prevent the odd Contactor from buzzing occassionally?

I am planning to clean the surface area with "Deoxit Contact Cleaner" which is more expensive but apparently helps break down oxidation not just clean and blow off grime. I was curious if WD40 Contact Cleaner would do the same job, as it is readily available and just clean the surface with fine emery cloth? ( which I heard leaves residue that may cause pitting)?

Thanks for any feedback!

 

[zbang]

Unlikely that "dirty" contacts are the problem. I'd check for crud that keeps the relay core and contact arm from doing their full-travel and that all the fasteners are tight.

Do not use actual emery cloth, the dust is conductive. Do not use course sand paper (or a file) at all, it can remove any plating from the contacts (1500 grit paper, gently applied, should be OK). I sometimes clean contacts with a piece of paper bag pulled between closed contacts; wet with rubbing alcohol for difficult cases.

And some contactors just hum; don't ask why .

 

[powerplay]

Thanks for the insight!

I had meant the relay core and contact arm.. it has carbon on it... perhaps small amount of filings are the culprit...

I am picking up contact cleaner, but trying to find Deoxit D3 to help remove the carbon and hopefully the proprietary “antioxidant”will help maintain the surfaces.. curious if anyone had used it, as it sounds like an thin film but it’s been around 60 years apparently, not cheap and difficult to find on an shelf..

 

[powerplay]

Unlikely that "dirty" contacts are the problem. I'd check for crud that keeps the relay core and contact arm from doing their full-travel and that all the fasteners are tight.

Do not use actual emery cloth, the dust is conductive. Do not use course sand paper (or a file) at all, it can remove any plating from the contacts (1500 grit paper, gently applied, should be OK). I sometimes clean contacts with a piece of paper bag pulled between closed contacts; wet with rubbing alcohol for difficult cases.

And some contactors just hum; don't ask why .

... and if some contactors like to hum... these ones occasionally play an amped up heavy metal rock concert !!