That's exactly what it is. A plain Jane doorbell transformer. Just
disconnect the low voltage wires and check your doorbell







"Nate Nagel" wrote in message
...
wrote:
There's a metal box attached to the side of my smoke alarm box with
what looks like a phone line coming out of it. It travels between the
joists for about 10' before disappearing into the subfloor above. I'd
like to disconnect this box to mount the smoke detector in a new place
(and will reattach then if needed).

PIc is at: http://img89.imageshack.us/img89/8822/img0693st8.jpg

Thanks!

Sure looks like a doorbell transformer to me. You could always disconnect
it and see if your doorbell suddenly stops working.

I suspect that you have a "tandem" type 120VAC smoke detector based on the
14/3 leaving that box. Generally the red wire is used as a tandem
connection between the smokes so if one alarms they all start sounding.

nate

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