Cord and plug furnace

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mbrooke

Batteries Included
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United States
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Technician
Does flexible cords or appliances in the NEC prohibit a gas furnace from being cord and plug connected? HO wants to be able to use the furnace on a generator without having to connect it to the home.
 

geochurchi

Senior Member
Location
Concord,NH
Occupation
Retired electrician
I had the same situation and I asked the code instructor ,who is very knowledgeable ,and he said yes it could be considered an appliance and could be cord connected,however the furnace is normally in a basement and would require it to be plugged into a GFCI protected outlet,not sure that would be the best practice.
Geo
 

iwire

Moderator
Staff member
Location
Massachusetts
Appliance or not it must be listed for cord and plug connection to use it that way

And yes I know some areas ignore that.
 

norcal

Senior Member
Appliance or not it must be listed for cord and plug connection to use it that way

And yes I know some areas ignore that.[/QUOTE]


Pretty common around here to have cord and plug connected attic mounted furnaces but I suspect that your opinion is more correct.
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Okay read what Petersonra posted. I don't think a furnace qualifies here.

422.16 Flexible Cords.
(A) General. Flexible cord shall be permitted (1) for the
connection of appliances to facilitate their frequent interchange
or to prevent the transmission of noise or vibration or
(2) to facilitate the removal or disconnection of appliances that
are fastened in place, where the fastening means and mechanical
connections are specifically designed to permit ready removal
for maintenance or repair and the appliance is intended
or identified for flexible cord connection.
 

Dennis Alwon

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Location
Chapel Hill, NC
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Retired Electrical Contractor
I think what Bob was stating about 110.3(B) was that the instructions probably do not allow a flexible cord unless the cord is listed for the purpose. Most gas furnaces do not allow a cord and plug connection.
 

augie47

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Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Here's an e-mail I received from UL when I questioned it a year or so ago.
Unsure if there have been any changes but the references are there.

[FONT=&quot] Gus,[/FONT] (copy of e-mail )

[FONT=&quot]This is the information that I have been able to locate;[/FONT]

[FONT=&quot]The basic standard used to investigate the refrigeration portion of the products in this category is [/FONT][FONT=&quot]ANSI/UL 1995[/FONT][FONT=&quot]. The basic standard used to investigate the gas heating portion of the products in this category is ANSI Z21.47/CSA 2.3, "Gas-Fired Central Furnaces."[/FONT]

[FONT=&quot]For gas furnaces, UL has few listings, and those are part of rooftop units - permanent supply connection is employed. CSA has most of the listings, as well as ETL. [/FONT]

[FONT=&quot]The applicable standard, ANSI Z21.47/CSA 2.3, Gas-Fired Central Furnaces, is quite vague on requirements for supply connection. This is typical of the electrical requirements of all CSA gas standards.[/FONT]

[FONT=&quot]This is relative to permanent wiring connection.[/FONT]

[FONT=&quot]1.18.14[/FONT]
[FONT=&quot]A service junction box having provisions to accommodate fittings for metal-clad cable or conduit shall be[/FONT]
[FONT=&quot]provided for the permanent connection of the line-voltage supply circuit. This box shall be located on a[/FONT]
[FONT=&quot]part of the assembly that does not require movement for normal servicing and adjustment.[/FONT]

[FONT=&quot]There is mention of strain relief of a power supply cord:[/FONT]

[FONT=&quot]1.18.20[/FONT]
[FONT=&quot]Strain relief shall be provided for all conductors leaving an enclosure. For low-voltage wiring, strain relief at[/FONT]
[FONT=&quot]the point of exit from an enclosure is not necessary if, by wire location or support, protection is provided[/FONT]
[FONT=&quot]against accidental strain. If the furnace is supplied with an external power supply cord handling greater[/FONT]
[FONT=&quot]than 50 Volts then a pull test shall be conducted.[/FONT]

[FONT=&quot]Generally speaking, gas furnaces should have permanent power supply connection. But if you see otherwise, check for the certification/listing mark that is applied, and contact that agency as it likely will not be UL. Based on the vague information contained in ANSI Z21.47/CSA 2.3, "Gas-Fired Central Furnaces," if there is a statement as you indicated that a Central Furnace is not ?readily removable for repair and maintenance.? then I would concur that an AHJ could state that this type of equipment was not in compliance with NEC section 400.7(A)(8). Based on the language used in 400.7(A), this is an all inclusive list unless 400.7(A)(10) can be used such as in 422.16. With that said, even 422.16(A) based on the language would not permit this type of equipment to be connected by cord and plug since again, CSA stated a Central Furnace is not ?readily removable for repair and maintenance.?[/FONT]

[FONT=&quot]Hope that is somehow is helpful.[/FONT]
[FONT=&quot]

Jeffrey A. Fecteau C.B.O., E.C.O
Lead Regulatory Engineer
Regulatory Services
Underwriters Laboratories
Wyoming, MN. 55092[/FONT]
 

iwire

Moderator
Staff member
Location
Massachusetts
Here's an e-mail I received from UL when I questioned it a year or so ago.
Unsure if there have been any changes but the references are there.

Thank you. :)


mbrooke, don't get me wrong, I think this is kind of a silly restriction but IMO it is a restriction that exists none the less.

With dishwashers for instance the instructions actually reference a cord and plug accessory kit and you must use that one. You can't (well not supposed to) just use any old appliance cord on it, you must use the cord referenced in the instructions. I tried to find the EC&M article on this topic but had no luck.
 

iwire

Moderator
Staff member
Location
Massachusetts
mbrooke,

Check out this UL position on replacement cords ...... they are out of control, there is no reason to put this much thought into power cords.


Question: Listing mark

Recently, I came across a Listing Mark on an electrical power cord, which indicated that ?only the Listed Power Supply Cord? was covered. We thought that marking requirements no longer applied to power cords. Can you please clarify?



Answer

The product you mentioned was probably an older power supply cord. At one time, UL did permit power supply cords for connection to electrical appliances to bear Listing Marks indicating that such cords were in compliance with UL Standards for Safety. Although the product identifier on the label indicated that the product covered by the Listing Mark applied only to the power supply cord, UL discontinued marking power supply cords because consumers were under the mistaken impression that the Mark applied to the entire electrical appliance.

Presently, power supply cords for connection to appliances are required to be bulk packed and only the container is permitted to bear the UL Listing Mark. If an individual power supply cord is provided as a replacement, then the cord will bear the Listing Mark, which must identify the product as a ?Replacement Power Supply Cord.?

http://iaeimagazine.org/magazine/20...uipment-replacement-during-natural-disasters/
 
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