dennis48755
I was considering how to help my friend with a temporary method to connect his furnace to his Generac XG6500 portable generator during an outage.

I say temporary because he is planning on talking to an electrician about installing a whole house standby generator next spring.

I first thought of simply installing a 3-way switch in the romex feed to the furnace with an inlet receptacle for the generator to switch the hot wire between the line-in and the inlet receptacle?

But then I got concerned about tying the neutral house wiring to the neutral in the generator inside the switch box.

Would a DPDT switch be more appropriate? Any specific switch suggestions (part numbers)?

Does this sound ok? Or are there other suggestions?

Thanks
Dennis
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Hodgy
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30 years ago I used a portable generator as standby for my furnace. I did not have a DPDT transfer switch and I did not back-feed through a breaker.

What I did was install a normal receptacle box on the 14/2 wire from the breaker box to the furnace. The receptacle box was adjacent to the furnace.

When/if we had a power outage in the Winter, I would unplug the furnace from the box and plug it into a extension cord that I ran from the generator output receptacle.

Simple but it worked. Probably contravened a code but better than freezing.


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78buckshot
That's the easy safe way to do it without any complicated switching.
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dennis48755
Good idea Hodgy, thanks for the suggestion.

Dennis
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patmurphey
Except for the codes that require hard wiring of furnaces. Reliance, Generac and EZ Generators make reasonably priced single circuit transfer switches for furnaces. Google "furnace transfer switch".
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Birken Vogt
This is a big debate. It seems to vary by region. Around here almost all homes and businesses have the furnace cord and plug connected.
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John R
Birken Vogt;37128 wrote:
This is a big debate. It seems to vary by region. Around here almost all homes and businesses have the furnace cord and plug connected.


This is how I'd do it, cheap, easy, and foolproof.
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patmurphey
Put it down as code that is commonly violated, but code, nevertheless. Furnaces don't come from the factory with a cord and plug, as do other appliances, like refrigerators or washer/dryers.
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MEC
This one looks pretty decent for your application.
Heezy HTS15-MAN Generator Transfer Switch Powers Gas Furnace, Boiler or Pumps up to 1875 Watts 15 Amp One Circuit [url]https://www.amazon.com/dp/B00BQMDOKO/ref=cm_sw_r_cp_awd_MRVHwb39CV2Z1[/url]

If it were me, I would use a mechanical interlock and utilize the Generacs 30A twist lock with an exterior power inlet box.
Then you can manually activate all the circuits the generator can support.
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dennis48755
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This one looks pretty decent for your application


Thanks MEC, I appreciate the link. Since this temporary (6 months or less) I decided to go with the cord & plug suggestion.

My friend is contacting an electrician to install a whole house standby generator.

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If it were me, I would use a mechanical interlock and utilize the Generacs 30A twist lock with an exterior power inlet box.
Then you can manually activate all the circuits the generator can support


I totally agree, this it is what I did for myself with a 15KW Generac Quiet Source before I installed my 16KW Generac Guardian 6462 3 months ago.
It worked very well for 10 years. So nice to not have to deal with gasoline any more. Neverless lugging that Quiet Source out of my garage, how they can call that portable?

Thanks again,
Dennis
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MEC
Yup, the cord and plug will work just fine. In fact, I have done this in the past when I worked as an apprentice a long time ago in a galaxy far far away.
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