wrote in message
...
Recently there is sometimes a loud hum coming from an electrical box
above the dropped ceiling in our office. We went up and opened the box
and saw that it is a Siemens/Furnas 42AF25AF magnetic contactor.
I thnk it controls the 220V fluorescent lighting in the lobby.

Where can I get a replacement and is it easy to swap out myself?

Thanks

If you put the number in Google you get about 30 places like this:

http://www.emotorstore.com/productDe...A_brandID_E_26

You should be able to replace it with just a screwdriver or two. Just be
sure you test the power to make sure you cut off the correct breaker feeding
it. There may be two breakers. One for the main contacts and another for
the coil. That may be for a photo cell that cuts off and on some outside
lights instead of the lobby lights you think it does.