On Thu, 02 Feb 2012 17:16:11 -0600, wrote:

On 2 Feb 2012 15:08:43 -0500, (David Combs) wrote:

Here's what I want to do.

I've got steam/boiler heater, runs on gas, the only electricty
needed is to run the (solenoid?) thermostat, basically.

It's powered via a cable (covered in flexible metal tubing)
that connects into the wall 110-AC line.

What I want to do is get that changed from that direct connection
to the wall, to instead end in a grounded male plug.

This solenoid is most likely operated by a transformer with a secondary
voltage of around 24 volts.

Working on low voltage wiring is easy to do and should not need to
follow a lot of codes. Therefore, the simple solution is to not touch
the AC supply voltage at all. Instead, buy an extra transformer to be
powered from the generator. Install a DPDT (Double pole double throw)
switch in a box, and connect this to secondary of both transformers.
When the switch is flipped in one direction, the furnace will run the
transformer from the power line. When flipped the other way, it will
run from the generator. Label the switch so you know which way to flip
the switch.

You can buy a switch like this at Radio Shack. You can also buy small
aluminum boxes there to install it after drilling some holes in the box
for the switch and the wires. A DPDT switch has 6 terminals on the
back. The 2 middle ones go to the 2 wires going to the furnace. The 2
terminals on the left go to the transformer from the generator, the two
on the right go to the 2 wires from the line powered transformer.

Find a buddy who plays around with electronics to help if you need help.
There are ham radio guys and electronics experimenters all over the
country. Maybe the Radio Shack clerk knows of someone, or call a few
local TV repair shops.

Be sure to buy a transformer MADE for your furnace. Call a furnace
repair shop.

Problem solved!


Won't run the exhaust fan or any pumps etc.