ECN Forum Forums Code Related Discussion NEC & other Code issues Is this legal?

I may be having a brain f*rt but I can't find the code section that prevents burying a doorbell transformer in the wall.
460.1 ex 4 seems to take that whole article out of the mix.
Chapter 3 is out for 725 circuits and I don't see anything in 725

I must just be missing it.

I would object on the grounds that such an installation is un-servicable without an access portal.

If such a cover/door permits access....

As for myself. I just install a 4 square, deep, and cover it with a 2-gang ring and flat cover.

IMHO, even such a low-power transformer needs some air space for convection cooling.

I would certainly try to get a better installation but if you run into one of those "sea lawyer" contractors, which article do you cite?

I encountered this situation years ago in some new houses we were wiring in extreme northwest New Jersey. They were 100% finished homes on slabs, no unfinished space whatsoever. No furnace, no boiler, just electric baseboard heat. My boss insisted upon just putting the transformer inside the panel and keeping the amount of exposed bell wire inside the panel to a minimum.

Obviously, this didn't fly with the inspector. He suggested what seemed to do well as a work-around. We attached the transformer to the bottom of the panel using the attached nipple and locknut, then we placed a two-gang mud ring to the stud below that permitted full access to the transformer. A two-gang blank plate finished it up.

Not exactly the best way to do it, but it satisfied the inspector for access.

Ed that was the other side of the discussion, putting the transformer in the panel but 725.136 pretty much shoots that down.

LV transformers usually are in the basements. On occasion the technique Ed has above works well.

We see them in the attic, usually right above the doorbell in the first box they can hit. It might be tricky finding them in the insulation.

Greg,

Any place in a garage where you can mount them on the surface? I looked into the code book for a ruling, but haven't seen one yet. Other than accessibility to equipment.

Thinking along this, the xfr under the panel w/mud ring could be an issue, if...
Wall cavity is to be insulated. Usual panel location is a garage, outside wall. The electrical inspector sees rough before insulation, and final when all is said & done.

Electric baseboard with a transformer implies that there is a contactor involved somewhere. Can the transformer be located with the contactor?