RBM wrote:
Just note where the wires of the existing transformer are attached and
connect the new one the same. Make sure your wire nut connections are tight
"Bill Green" wrote in message
m...
I need to replace the transformer for my door bell and I have some
questions
on good wiring practices.

The existing (defective) transformer is attached to a metal junction box
in
the middle of a cable whose primary duty seems to be providing power to
the
furnace fan motor. There is also a porcelain light bulb socket (luminaire
seems too fancy a word for this fixture) attached directly to the 'broad'
face of the junction box. This house is 40 years old so who knows what's
been done around the wiring, I've had surprises before.

I expect that when I lock out the breaker and open the junction box there
will be 4 black wires on one wire nut (1 black wire coming in, 1 black
wire
going out, 1 black wire for the luminaire, and 1 black wire to existing
transformer), 4 white wires on another wire nut (similar distribution as
for
black wires), and 3 grounds on a third wire nut (same as before except
that
the porcelain luminaire likely isn't grounded) or else attached to the
metal
box.

Is this a realistic assumption for a properly designed connection?

The reason I ask is that I had a another set of assumptions for a similar
junction box that was on a switched circuit. Here the reality didn't match
my preconceived notions; instead the white wire from the bathroom
ventilator
fan was attached to a sloppy-looking birds nest of ground wires; and
that's
the only way it would work.

Also, is it all right to connect 4 wires with one wire nut? Information
from
Ideal shows UL listed wire combinations for number/size of conductors for
each model number of Wire-Nut(R), so presumably this is okay. But is this
commonly done as good practice and relatively safe? Would it be better to
pigtail off so that I have 3 conductors under one wire nut with the
pigtail
connecting the existing light and the replacement transformer with another
wire nut?

thanks!




Hi,
First, turn off 120V going to the x-former. I'd buy a heavy duty
x-former which will last longer. It is just s step down x-former
120V AC to 24V AC.