ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Any women electricians here?
by gfretwell - 01/17/22 01:44 PM
12 Lead Motor Connection Weird
by Elektrik - 01/12/22 11:09 PM
Well There's your problem.
by gfretwell - 01/08/22 12:17 AM
Happy New Year!!
by HotLine1 - 01/04/22 09:50 AM
Sangamo s309.2
by Robski - 12/31/21 04:54 PM
New in the Gallery:
240/208 to a house
240/208 to a house
by wa2ise, October 9
Now you know.
Now you know.
by Tom_Horne, September 7
Who's Online Now
1 members (gfretwell), 42 guests, and 16 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
#74275 01/19/07 11:54 AM
Joined: Aug 2004
Posts: 55
W
wendel Offline OP
Member
Can a furnace used to heat a home be plugged into a switched outlet on a single, dedicated circuit?

Joined: May 2005
Posts: 984
Likes: 1
G
Member
Not the way that I read 400.7.

BTW, you hit one of my pet peeves.
There is no definition of "dedicated", no matter how many times people think that it's in the Codebook.
I have had "dedicated receptacle" and "dedicated circuit" called for on many, many jobs...and it never meant the same thing one each one.
It either only has 1 load, or 1 type of load, or only feeds 1 area, or only feeds 1 room.
I've even taken to responding to requests for dedicated circuits with "what do you mean 'dedicated'? Does that mean that it always votes Republican"? At least that wise-acre answer opens up a discussion that if I don't know what they really want, I can't give it to them.

I think that your question was intended to mean ...switched outlet on a separate circuit.

My answer is still nope.


Ghost307
Joined: Jul 2004
Posts: 9,677
Likes: 9
G
Member
422.16 is probably more on point. You really bump into this language " ... the appliance is intended or identified for flexible cord connection."
You *might* be able to use the "vibration" and "service" language (with tongue firmly in cheek) otherwise.
I doubt any furnace manufacturer "identifies" his equipment as being suitable for cord and plug connection.
I suppose if you could get a letter from the manufacturer's engineering department, you would be good to go.


Greg Fretwell
Joined: Jan 2005
Posts: 5,316
Cat Servant
Member
Out West, it is quite common to connect a furnace with a cord and plug. This has been particularily true when the electricity is only used to power a fan and an electriconic igniter.

I see a requirement that the furnace be on a 'dedicated circuit.' I understand this to mean that the breaker serving the furnace serve only the furnace, an associated equipment. For example, folks are installing electronic air cleaners, humidifiers, and the like into a 'air treatment assembly.' (to coin a phrase).

Now, there is the matter of controlling the furnace. I would have no problem with a timer, or occpancy sensor, being connected to a furnace. Indeed, a person might want a remote "disconnect" to shut off the furnace when the property was vacant - as in a holiday lodge. Many hotels also have a central control that can disable the individual thermostat in each room.

We want a dedicated circuit, so that an unrelated fault will not disable the heating equipment.

My concern with a switch controlled receptacle being used is the accidental disabling of the furnace. While I don't think the code specifically addresses this isue (so technically it would be allowed), I question the wisdom of this design.

Joined: Sep 2001
Posts: 806
N
Member
I had a request to install a setup like that once, so that the furnace (gas) could be plugged into a portable generator during a power outage.

I ran it by the AHJ, and he was fine with it, as long as I used rough service cord and a twistlock plug/receptacle. Had to make up a special extension cord with a mating twistlock for use with the generator, as well. Setup is still in service, AFAIK.

Joined: Feb 2003
Posts: 231
R
Member
As was already said, it would depend on the manufacturer's instructions.
Here we hard wire them in off of a single pole switch that is used as the disconnect. Usually located at the bottom of the stairs so if the furnace is on fire you don't have go close to it to cut the juice. It is on its own cicuit. We put a red switch plate on it that says "emergency" so you remember what it is for and don't accidentally turn it off.
http://www.tnb-canada.com/en/catalogues/online/comresconstruction/pdf/c1/boxes_18_eng .pdf

This is code here in Canada when the panel, which would normally be the disconnect is in the vicinity of the furnace. They don't want you to have to walk by the furnace to disconnect it if there is an emergency. Allot of times the panel is in the vicinity of the furnace so that is why we do it here.

No switch required if the panel is located between the furnace and the point of entry to the area where the furnace is located.

I know you are not from Canada but thought I would write it anyway because I like the reasoning behind our rule.

[This message has been edited by RobbieD (edited 01-19-2007).]

Joined: Jun 2005
Posts: 821
S
Member
Why would the receptacle be switched?

If the furnace was wired with a cord, then the cord would meet the required disconnecting means.

I've never had to wire a furnace this way.

Joined: Jan 2007
Posts: 20
1
Member
I second what renosteinke said, out here in California, we plug the FAU into a receptacle that's on an INDIVIDUAL (The correct term for dedicated) circuit.

And as ShockMe77 says, why add the switch, it's not needed.

Joined: Apr 2002
Posts: 7,288
Likes: 4
Member
The New Jersey way, as I know it;
Branch circuit from panel to furnace location. Hard wired to furnace. May have a single receptacle at/by/on furnace for accessory. May have a duplex if two accessories. (Single recept in 'unfinished basement area) Safety switch (disconnect) on/at/by furnace.

Furnaces installed in attics may have an additional safety switch by the point of entry into the attic.

As noted above, the switch at the top of the basement stairway for "emergency use' USED to be the norm, but has faded away.

The "safety" switches were required either by the Fire Code, or Mechanical Code, but not NEC to the best of my knowledge.

I have never seen a furnace cord and plug connected here, but...hey you never know.

John


John
Joined: Jul 2004
Posts: 9,677
Likes: 9
G
Member
Robbie's description is what I remember from Md. We always had a switch wioth a red plate, at the entrance to the furnace "space". If it was in a utility room the switch was at the door. If it was out in the open in an unfinished basement it was usually at the top of the stairs.
A lot of times it would be taped up so you couldn't hit it by accident.

Down here there is no such thing as a furnace. All we have is toaster wire in the air handler or a couple 2.5Kw wall heaters.


Greg Fretwell
Page 1 of 2 1 2

Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
SafetyWired
SafetyWired
Pa, USA
Posts: 44
Joined: July 2013
Top Posters(30 Days)
NORCAL 3
grich 1
Popular Topics(Views)
287,906 Are you busy
220,061 Re: Forum
206,054 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5