What is this??

I found this today in 200 AMP Cutler Hammer service panel. It did not appear to be connected to anything. Is it some type of surge protector?

Thanks, In advance for your input.

A relay. Not sure what it was for.

Motor control relay. Probably for HVAC or refrigeration? Never seen one before.


Contact’s for lights or sprinkler maybe , I would just recommend it to be removed no longer in use.

That’s not a motor control relay. It is a 4-pole lighting contactor. This way one resi-grade wall switch can control up to four full lighting circuits.
Maybe for outside floods and landscape lighting combined?

In commercial work whole lighting panels are switched this way. Those make a nice BANG when switched on. :mrgreen:

It’s called a “definite purpose contactor” by Cutler-Hammer. Maybe a form of heavy duty motor switch (A/C or other compressor?)

You need to read what Speedy just posted. These are very commonly installed in panels to control lighting. When an electrician sees a 4-pole version, that a dead give-away that it was used to control lighting as opposed to a motor load. If I see a contactor in a panel, as a professional, I’d never ever think motors or AC. Always think lighting.

The two 3-pole ones I have in my house are fired by a timeclock and feed 6-20 Amp Christmas light circuits…

That must be some pretty hardcore decorations you have. Sounds like a lot of work every year.

It takes about a week, but is well worth it!