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Discussion Starter · #1 ·
Hi, I have a small generator. I'd like to wire a clean interface so that I may power a furnace and a couple of appliances during a winter power failure (without breaking the bank). Below is a drawing of how I thought I might do it. I'm not sure if the ground is sufficient (it's 12 gauge ground wire) or if I should run a dedicated ground back to the panel. Also I know it's not code to put a plug on a furnace but it will still be on a dedicated circuit. What are your thoughts?

658685
 

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Naildriver
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You would probably be better off installing a 30 amp breaker in the upper right slot (moving breakers as needed) and installing a lock out so the main must be off before the 30 amp breaker can be turned on. Then within your panel, turn off all the breakers except the ones you need to power during the outage. 3200 watts isn't a great size generator, so in the mean time, you could be shopping for a larger one and use the same set up. Your cord/inlet wiring to the panel is correct.
 

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By code in most places, the furnace is required to be hard wired, and have a dedicated circuit. A receptacle doesn't satisfy that. The furnace switch must be included in that dedicated circuit. (usually within reach of the service area of the furnace, but codes can differ on that part.)

I assume this is a gas, propane, or oil furnace?

Cheers!
 

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I know it's not technically code compliant, but I just wired in a pair of extension cord plugs into the cable to the furnace. If I need to power the furnace from the generator, I unplug it from the house wiring and plug it into the cord from the generator.
 

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Usually Confused
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As an aside to your question, you might want to determine if you generator will successfully power your furnace. Many new hi-tech furnaces don't play well with generators with high distortion.
 
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Standard duplexes cannot be fed from a 30 amp circuit.

6ou can but a single circuit transfer switch for the furnace.
 
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Discussion Starter · #7 ·
Hi thanks for the responses. To answer some questions, it is a high efficiency propane furnace, the generator is an inverter generator so stable power for more sensitive equipment. Thanks for the input on the code regarding hardwiring furnaces.

Do you think it is ok to use the house ground and is 12 gauge big enough?
 

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Discussion Starter · #8 ·
Standard duplexes cannot be fed from a 30 amp circuit.

6ou can but a single circuit transfer switch for the furnace.
Thanks, I see what you mean

It's because you could potentially try to draw 30 amps through one duplex which is beyond it's rating. I'd have to have two 30 amp duplexes or something for it to be safe and they probably don't exist or are really expensive.
 

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Discussion Starter · #9 ·
You would probably be better off installing a 30 amp breaker in the upper right slot (moving breakers as needed) and installing a lock out so the main must be off before the 30 amp breaker can be turned on. Then within your panel, turn off all the breakers except the ones you need to power during the outage. 3200 watts isn't a great size generator, so in the mean time, you could be shopping for a larger one and use the same set up. Your cord/inlet wiring to the panel is correct.
I like the idea of the 30 amp generator breaker at the panel, I even have the space for it but the panel is on the opposite side of the house from the propane bib I am running the generator off of. I can see it would be a better way to do it though. My panel uses federal pioneer breakers. How does the lock work between the main and generator breaker?
 

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You can get one of these for about $300.
Simple to install next to your panel, minimal wiring.
658718
 

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Naildriver
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My panel uses federal pioneer breakers.
Not the best conclusion to this thread. Do a search for Federal Pioneer panels and breakers. Your research will help your decision making with that respect.
 

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Hi, I have a small generator. I'd like to wire a clean interface so that I may power a furnace and a couple of appliances during a winter power failure (without breaking the bank). Below is a drawing of how I thought I might do it. I'm not sure if the ground is sufficient (it's 12 gauge ground wire) or if I should run a dedicated ground back to the panel. Also I know it's not code to put a plug on a furnace but it will still be on a dedicated circuit. What are your thoughts?

View attachment 658685
The code compliant way to do this is to install a double pole, double throw, center off switch in place of the existing furnace servicing switch. The common terminals get connected to the furnace neutral and energized conductor. One of the selectable sets of contacts will connect to your 30 ampere travel trailer inlet. The other pair of switched contacts attaches to the neutral and energized conductors from the panel the furnace circuits fuse of breaker is located in. Customary practice is up is panel power and down is the travel trailer inlet connection. Center is off on all such switches.

If you mean the other 3 outlets in your drawing to supply other loads, as it appears that you do, then you will need to buy a double pole, double throw, center off switch rated at 30 amperes. They are a little harder to find but you can order them on line through any of the large home center store web sites for delivery to the store for pickup. That switch can then change the source for a 2 slot panel from the 30TT inlet to a 30 ampere circuit from the panel. One of the breakers in that small panel will be for the furnace. The other would be for the other 3 receptacles. None of the receptacles would be mounted on the furnace. This would cost you a lot less than any of the factory built generator transfer switches and would be just as safe as those are.

Both breakers would be 15 amperes. If you use 20 ampere breakers there is a chance that you will trip the generators breaker instead of the ones inside the house. That will mean going outside to reset it. That would sure be a lot of fun under blizzard conditions.

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One of these is about $60. Is far simpler to install, just 1 breaker and 4 wires (3 for you).




Prices and availability vary by panel. It has to be the correct one for your panel.

It allows you to backfeed your main panel safely, meaning you can power any (not every) 120V load in the entire house, and it takes care of the appropriate ampacity for the branch circuit, and it supports AFCI and GFCI unlike certain other options.
 

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One of these is about $60. Is far simpler to install, just 1 breaker and 4 wires (3 for you).




Prices and availability vary by panel. It has to be the correct one for your panel.

It allows you to backfeed your main panel safely, meaning you can power any (not every) 120V load in the entire house, and it takes care of the appropriate ampacity for the branch circuit, and it supports AFCI and GFCI unlike certain other options.
Finding one for a federal Pioneer is going to be difficult. I suggest the generator sub panel kit. Just as easy to install and probably cheaper, considering the panel he has.

Cheers!
 

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Discussion Starter · #16 ·
Thanks for all the help. I will do some reading on it. I know the issues with federal pioneer panels, I have them blocked up pretty tight so none are hanging. Poor design. Plus since the pandemic they are impossible to get. I priced out the double throw double pole switch option but by the time I add everything up I might as well buy the panel kit. That's probably the way I'll go. Thanks again
 

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Hi thanks for the responses. To answer some questions, it is a high efficiency propane furnace, the generator is an inverter generator so stable power for more sensitive equipment. Thanks for the input on the code regarding hardwiring furnaces.

Do you think it is ok to use the house ground and is 12 gauge big enough?
High Efficiency furnaces often have self protective circuits which can detect the absence of any common point on the ground and neutral and not start. They will give you an error code that your instruction manual will tell you means open ground. If the generators neutral is not bonded to the frame then that is what would occur if you plugged the furnace directly into your generator by installing a flanged inlet and a small transfer switch in the place of your furnace's servicing discconect. When the neutral conductor is transferred by the transfer switch it no longer is connected to the Main Bonding Jumper in the Service Equipment cabinet.

Flanged inlet.jpg

Check your generators manual to see if it's neutral conductor is bonded to the frame. If it isn't then the manual may tell you how to do that. If it is not covered in the manual then contact the manufacturer for that information.

Another way to overcome that is to use a single pole, double throw, center off switch to switch only the energized (hot) conductor. [If you cannot locate one you may be able to order it on line or you can use only one side of the more common double pole type.] That way the neutral conductor's connection to the Main Bonding Jumper at the panel will be detected and the furnace control will be happy. DO NOT substitute an added connection between the neutral conductor and the Equipment Grounding Conductor (EGC) anywhere else! Once a neutral conductor leaves the service equipment enclosure it MUST NOT be connected to ground anywhere else. Making a "bootleg" connection somewhere else in the wiring could expose you and your family to a risk of electric shock.

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Tom Horne
 

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Discussion Starter · #18 ·
One of these is about $60. Is far simpler to install, just 1 breaker and 4 wires (3 for you).




Prices and availability vary by panel. It has to be the correct one for your panel.

It allows you to backfeed your main panel safely, meaning you can power any (not every) 120V load in the entire house, and it takes care of the appropriate ampacity for the branch circuit, and it supports AFCI and GFCI unlike certain other options.
Thanks I'd like to look this up but can't find it on google, Do you know the model or name?
 

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Thanks for all the help. I will do some reading on it. I know the issues with federal pioneer panels, I have them blocked up pretty tight so none are hanging. Poor design. Plus since the pandemic they are impossible to get. I priced out the double throw double pole switch option but by the time I add everything up I might as well buy the panel kit. That's probably the way I'll go. Thanks again
I doubt that you will find a breaker interlock kit for your Federal Pioneer panel. The cost of a 2 breaker panel to provide one breaker for the dedicated furnace circuit and one breaker for the other loads is $16. The cost of a switch to transfer the 2 breaker panel between 2 sources of power is $35. Every thing else you already planned to buy. What other transfer arrangement is going to cost less than $51?

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Discussion Starter · #20 ·
I doubt that you will find a breaker interlock kit for your Federal Pioneer panel. The cost of a switch to replace the furnace servicing disconnect switch and transfer the generator between 2 sources of power is $35. The cost of a 2 breaker panel to provide one breaker for the dedicated furnace switch and one breaker for the other loads is $16. Every thing else you already planned to buy. What other transfer arrangement is going to cost less than $51?

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Tom Horne
Thanks for the reply. Would the 2 breaker panel you mentioned have a 30 amp main breaker and 2 15 amp sub breakers? A link would be greatly appreciated.
 
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