On Mon, 9 Dec 2013 13:34:40 -0500, "Ralph Mowery"
wrote:


"Jennifer Murphy" wrote in message
.. .
compressor motor.

It also requires a minimum load of 40 watts. Why is that? Why would it
be damaged if the load were just a 25 watt bulb or a few 5 watt LED
candelabras?



It needs a minimal load. It will not be dammaged, but may not work. It is
using the load on the end to get a sort of 'fake neutral'. The switch is
getting the incomming power from the hot wire. As there is no neutral in
the box, there must be a return path so a small ammount of return power goes
through the load. Not enough power will go through it to light a 40 watt
light bulb, but some power is. Probably enough to give you a shock if you
touch the load side of the switch even if the light is 'off '.

OK. Thanks.

The other switch (the 740B) requires a neutral line, which I don't have
in the wiring in this old house. I guess there is no way to use that
switch in my situation, right?