Gas Central Heat Unit- Cord & Plug

Status
Not open for further replies.

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I seem to recall someone posting a NEC reference other than 400.8 or a UL reference prohibiting using a cord & plug as a disconnecting means for a gas fired central heat unit/air handler. Any input ?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I seem to recall someone posting a NEC reference other than 400.8 or a UL reference prohibiting using a cord & plug as a disconnecting means for a gas fired central heat unit/air handler. Any input ?

I recall that also but was it a NEC issue or a manufacturers instruction?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
It could be 400.7(A). I don't see where a furnace would fit those uses. Also water heaters, IMO, would not fit the bill.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
How about ANSI Z21.47. Cord and plug is not allowed on gas furnaces. I believe UL refers to this standard.


Great !
Do you happen to have a quote or a more precise referecne number ?
When I Google Z1.47 I get a list of other sections.
 

tryinghard

Senior Member
Location
California
Specifically how does the NEC address this, is it just about the listing? There are some things the NEC specifically disallows is this one?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Specifically how does the NEC address this, is it just about the listing? There are some things the NEC specifically disallows is this one?

The nec does not specifically address this issue . I did mention art. 400.7(A) so that is the closest I found. It sounds like an ANSI related issue which probably is in the manufacturers specs.?????
 

shortcircuit2

Senior Member
Location
South of Bawstin
Some of the new residential high efficiency gas boilers come set up with cord and plug connection.
The connection box inside a Buderus gas boiler that I just wired only had screw and clamp down points for cord type connection. I used MC and EMT to a juction box right beneath where the connection area for the boiler and came out of the JB with a short piece of UF to connect to the boiler.

shortcircuit2
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
There is a similar issue with a dishwasher. Some come approved with cord and plug while the others require you to use a cord and plug listed for the dishwasher. Obviously if the furnace comes with cord & plug and it is listed then there would not be an issue.
 

Mgraw

Senior Member
Location
Opelousas, Louisiana
Occupation
Electrician
augie47 I found this on ULs website.
Q.
Has UL Listed any cord & plug connected central air conditioning units, central heating furnaces or storage tank water heaters?
A.
No, for central air conditioning equipment and central heating furnaces.
These types of equipment have been Listed as suitable for permanent wiring installations only. They are Listed under UL product category Heating and Cooling Equipment (LZFE), located on page 216 in the 2009 UL White Book or may be found on UL?s Online Certification Directory at www.ul.com/database and entering the category code at the category code search field.
Only small capacity (5 gallon or less) storage tank water heaters or water heaters that are designed to permit removal for maintenance and repair can be cord and plug connected. The requirements are detailed in the Standard For Safety For Electric Booster and Commercial Storage Tank Water Heaters, UL 1453 as well as the Standard For Safety For Household Electric Storage Tank Water Heaters, UL 174.
 

renosteinke

Senior Member
Location
NE Arkansas
And folks didn't want to accept "UL Question Corner" as a source when I posted it ... :)

THAT particular UL answer is, unfortunately, misleading. It refers to electric heating equipment - NOT to gas equipment that might have but an electric igniter, blower, or circulating pump. Nor does it address the humidifiers, air cleaners, etc., that are also often accessories to the HVAC system. The UL spokesman quite carefully dodged the general question.

UL has recently clarified this point -at least regarding pumps- with a revision to one of their product standards (cord & plug is OK, within limits).

From the dishwasher and water heater discussions, I think it's safe to say that if something comes with a cord & plug, then that method is fine.

As for your installing a cord & plug for such an igniter, I think the issue is still unresolved. Personally, I'm inclined to say "no problem."
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
And folks didn't want to accept "UL Question Corner" as a source when I posted it ... :)."
After I read UL LFZE, I sent a message to Mgaw stating I could not find wording specifically prohibiting C&P. So if it helps your feelings :grin: it wans;'t accepted at face value :grin:

THAT particular UL answer is, unfortunately, misleading. It refers to electric heating equipment - NOT to gas equipment that might have but an electric igniter, blower, or circulating pump. Nor does it address the humidifiers, air cleaners, etc., that are also often accessories to the HVAC system. The UL spokesman quite carefully dodged the general question.

UL has recently clarified this point -at least regarding pumps- with a revision to one of their product standards (cord & plug is OK, within limits).

From the dishwasher and water heater discussions, I think it's safe to say that if something comes with a cord & plug, then that method is fine.

As for your installing a cord & plug for such an igniter, I think the issue is still unresolved. Personally, I'm inclined to say "no problem."

I agree that factory installed or accepted cord & plug is no problem. I lean toward 400.7(A)(8) not allowing it (therefore a violation of 400.8) in this case, but I'm trying to give the E/C benefit of the doubt.
 

John120/240

Senior Member
Location
Olathe, Kansas
After I read UL LFZE, I sent a message to Mgaw stating I could not find wording specifically prohibiting C&P. So if it helps your feelings :grin: it wans;'t accepted at face value :grin:



I agree that factory installed or accepted cord & plug is no problem. I lean toward 400.7(A)(8) not allowing it (therefore a violation of 400.8) in this case, but I'm trying to give the E/C benefit of the doubt.

So field installed cord & plug of comparable quality & UL listed, installed by a

qualified electrician is a violation? It doesn't make any sense.
 
Status
Not open for further replies.
Top