The CT area is forecasted to have a blizzrd, with the possible loss of
My question: I have bought a gas powered generator, as a Back Up. I
will, later, install a secondary breaker panel - for use under
generator power. That seconadry panel would provide power to our key
circuiots, including the furnace.
In the interim, is there a way I can power our nat gas furnace
electronics, from our BU generator.
Hopefully we will not lose power???
On Monday, January 26, 2015 at 11:17:26 AM UTC-5, bob_villa wrote:
What Rick outlines there is not code compliant. We've been through
this many times here. Code says that the only appliances that can
be used on a cord and plug are ones that are designed to be used that
way to allow servicing. Furnaces don't meet that test. There isn't
an install manual for a furnace I've ever seen that says you can put
it on a plug and cord of your choosing.
It's certainly not the worst thing I've ever seen and if he wants to
do that for the storm, I don't see a problem with that. There are other
people who have done it. Just that if he wants a long term solution,
expects to pull a permit, which is probably required in CT,
have it inspected, it may not pass. He could go ask the inspector.
It's also likely to get flagged on a future home inspection for sale,
etc. The correct way of doing it at the furnace is with a transfer
switch and inlet.
Think neighbor did it the dumb way:
He later got a transfer panel which is the way I did it.
That was my interpretation of the code.
So, I went down to the permit office and asked the inspector.
His response was that he'd never heard of such restriction and it
would be no problem. I would feel better if he'd acknowledged the
code statements before telling me it was no problem.
On Monday, January 26, 2015 at 11:03:57 AM UTC-5, Dave C wrote:
There are several ways. Ranging from code compliant to a suicide
cord. Given that it's already snowing, the code compliant method
window has likely closed. I've used the latter method for an
emergency. But then I know what I'm doing.
After this event, instead of a secondary panel, I'd look into
a lockout kit for your existing panel. Basically, you put an
new breaker into the first slot of your panel, move whatever was
there somewhere else. That breaker goes to an inlet. You can put
the inlet outside, where the generator would be used or put it
at the panel and use an extension cord. There is
a lockout slide that prevents that breaker and the main breaker
from being closed at the same time. Check for your panel to see
if one is available from the manufacturer. If so, get it. If
not, there is an aftermarket supplier:
The manufacturer supplied one is 100% code compliant. The latter
is likely acceptable, but some AHJs might have a beef.
Why anyone would put in another panel, move circuits over, etc,
when using a manual type generator is beyond me. The above
approach is low cost and allows you to run anything in the
house, manage the load at the panel, etc.
On Monday, January 26, 2015 at 11:03:57 AM UTC-5, Dave C wrote:
Before I had my generator wired into the breaker box (with a shut-out of co
urse) I had the furnace on a plug system. I put an outlet into the circuit
box above the furnace and put a plug on the cord coming up from the furnace
. When the power went out, I switched from the house current plug to the ge
nerator plug right next to it. Not up to code or high tech, but it kept us
warm through several power outages.
How big is the gennie and how much current does your house "Cruise" on?
If the gennie is small enough, consider a "Smart" transfer
switch/secondary panel that can shut down circuit "A" temporarily while
circuit "B" needs enough to otherwise overload the gennie.
Our house cruises on 800-1200 watts and runs comfortably on a 2KW
generator with a smart switch in control - as long as we delegate making
coffee, running the toaster and such to little propane stoves on the
The smart switch kicks in when older refrigerators with very high
starting surges need to start up. When that happens, lights go out in
the rec room and the computer equipment runs on UPS backup for about
We recently got a second 2KW generator that can run in parallel with the
first - more for redundancy than the added capacity - but when both are
online we can make toast, make coffee, and run the big microwave oven.
I've done it with a hot-water boiler while I lived in Alaska. My little
Honda 350W generator of the time was sufficient to run the circulator pump
and the control stuff on the boiler. I just disconnected the power feed to
the boiler, took an old extension cord and cut off the receptacle end and
wired that to the wires to the boiler using wire nuts. Ran the extension
cord outside the garage and plugged it into the generator and I was good to
go. The house was pretty well insulated so I just ran the generator long
enough to heat the house to 75-degrees and shut it down until it got down
to 65-degrees and repeated the process until the power poles got put back
up. I didn't even lose any of my tropical fish since I threw a heavy
comforter over the aquarium to keep some of the heat in.
Well, when I had my 2500 watt generator I added a receptacle to both
the furnace and the freezer/refrigerator circuits and put the two
circuits on one 220 volt pull-out (fuse panel). In case of a power
failure I could pull the fuse block and plug the generator into one or
the other with the suicide cord.
There is a way around it. Hardwire the furnace to a "disconnect
device" - which is just a junction box with a cord mounted with a
strain relief, which plugs into a SINGLE outlet, not a duplex - and
you are code compliant. A twist lock lug is recommended. The single
outlet is crucial to making it compliant as the furnace MUST be on a
Another way to do it is with a 3 way switch, hooking the furnace Live
connection to the center terminal, and line to one of the switched
terminals, and a line to the generator "port" on the other switched
terminal, with the neutral and the ground "T"d (joined with wire nuts)
in the box. (not neutral to ground, but furnace to panel to gen port
for both neutral and ground)
On Monday, January 26, 2015 at 8:02:07 PM UTC-5, email@example.com wrote:
If by port you mean an inlet, then I agree, that is code compliant.
Of course with less work you could install an interlock, breaker and
the same inlet on the main panel and power not only the furnace, but
anything else in the house too.
On Monday, January 26, 2015 at 8:57:38 PM UTC-5, Pico Rico wrote:
Here's a good discussion of the subject:
This is the most pertinent part:
*Appliances where the fastening means and mechanical connections are specif
ically designed to permit ready removal for maintenance and repair, and the
appliance is intended or identified for flexible cord connections [422.16]
, but only when used with attachment plugs [400.7(B)].
It's hard to argue that a furnace is designed to be readily removable for
maintenance. Even worse, it's clearly not intended or identified for use
with a cord and plug.
But, as has been reported here and in the past, some AHJs are OK with it.
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