wiring furnace for gennerator

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Moderators: Greg, Mark

Posts: 4
Joined: Wed Nov 13, 2013 9:46 pm
Location: Wayne, Ohio

Tue Jan 07, 2014 2:11 pm

Have a Have a 1998 Nordyne model # MMHA-070ABHR-5. Would like to wire for emergency generator use. is there a way other than going through a transfer switch?



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Posts: 5378
Joined: Wed Feb 28, 2007 8:01 pm
Location: Weedsport, NY

Tue Jan 07, 2014 5:51 pm

The only other Legal way is to unhook the furnace at a junction box and wire a plug on. Homes being powered by a generator need to be 100% removed from the power grid. I personally saw a power company worker get knocked hard during an Ice storm. The wires were on the ground in both directions from a house, he grabbed the wire and got knocked - generator running in the house.

"If I can't fix it, I can screw it up so bad no one else can either."

Posts: 622
Joined: Tue Nov 11, 2008 6:12 pm
Location: wisconsin

Tue Jan 07, 2014 9:46 pm

If this was mine I would do like Greg suggested and buy a pigtail cord to keep on hand. When the power goes out shut the main breaker off and then unhook the supply wires in the furnace and rewire with pigtail. Then just run an extension cord from generator to the furnace. This way you can run the furnace for a while and then unplug it and plug something else in like the fridge for a while. Switching back and forth.

A transfer switch is nice because it just flips on and then you can control what your generator powers by using your breaker panel. No wiring to mess with. But they can be expensive and need to be installed.

If the power company finds you with a generator hooked up to your panel and backfeeding their lines they will cut your lines or pull your meter and leave you sitting. They take this very seriously due to incidents like Greg mentioned.

Posts: 205
Joined: Sun Dec 05, 2010 5:34 pm
Location: Orefield, PA

Wed Jan 08, 2014 4:19 pm

If you are only trying to power your furnace, then yes. Go to a hardware store and buy one of those make you own plug kits. Or cut a piece of cord with the plug end attached. When the power goes out flip your main off and then take apart the power wiring on the furnace and wire nut it with the extension cord piece you have. Then you can plug it into the generator. Make sure to wire nut off the power wires that feed from the panel to the furnace just to be safe. I was doing this for awhile till I got my transfer switch put in. But yes, back feeding you panel can potentially kill a lineman if you open or forget to close the main breaker.
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