On 2/5/2012 11:25 AM, bud-- wrote:
On 2/4/2012 3:17 PM, wrote:
On Sat, 04 Feb 2012 10:16:26 -0600,
wrote:

On 2/3/2012 8:25 PM, wrote:
On Fri, 03 Feb 2012 20:37:07 -0500, wrote:

On 2/3/2012 7:13 PM, wrote:
On Fri, 03 Feb 2012 18:48:40 -0500, wrote:

On 2/3/2012 6:30 PM, mike wrote:
On 2/3/2012 1:34 PM, Horace Greeley wrote:
On 2/3/2012 7:22 AM, RBM wrote:
On 2/2/2012 11:05 PM, wrote:

I've seen furnaces connected with a twist-lock plug - it
meets the
requirement for a disconnect within reach of the
furnace.(takes the
place of a switch) and is also a foolproof way of connecting
to a
genset.

That maybe true in Canada, but it doesn't meet 422.16 of the
Nec, in the
U.S., at least not for your garden variety central heating
system.


Check with your local electrical inspector.

If done properly, ours said it was legal and safe to do the
plug and
cord setup.

His only recommendation was to use a 12 gauge appliance cord
set, proper
strain relief (not romex clamp) and a high-quality 20 amp
receptacle.

I went thru the same process.
Prevailing opinion is that devices permanently attached to the
structure
must be permanently wired. Heating system seems to be
permanently attached.
Reading the NEC, it appears that's what it says.

The Nec requires that it be designed to be unattached , and
removed for
servicing, for a cord and plug to be used. Not too many central
heating
systems that meet that criteria.

So, I went down to the permit office and talked with the inspector.
He said, "no problem; putting a socket in the box and plug on
the wire
will pass my inspection".

That's only the "B" part.
There IS another allowed reason.

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


A power failure every year or less can be considered "frequent
interchange". - if you don't wish to make a case for anti-vibration
(and you do not have a "compliant connection" or whatever you call
the
fabric connector on the duct hood.

Boy, you are one master of misinterpretation. It's referring to
interchanging the appliance. You don't replace your boiler because of
frequent power failures.
I would love to see you try and run your silly arguments by an
electrical inspector. They'd laugh you right out of the business.

They get inspected and passed all the time. And not just in Ontario,
or Canada.

And you determined that from your Ouija board?

Google it like I did.
It is being done and passed in Pennsylvania for sure.

Anecdotal evidence of "all the time". What a great idea.
Astrology works "all the time".


You and Evan generalize what is (allegedly) true where you are to the
universe.


You are generalizing about something you apparently don't know any
more about than I do.

Like RBM I am commenting on NEC requirements.

I agree with RBM.

To take a slightly different approach, use of cords is covered in
article 410. Uses permitted is in 410.7-A. Possibly relevant sections
a
"(6) Connection of utilization equipment to facilitate frequent
interchange.
(7) Prevention of the transmission of noise or vibration.
(8) Appliances where the fastening means and mechanical connections are
specifically designed to permit ready removal for maintenance...."

Sections 6 and 8 are not relevant to boilers in the US. You may have to
often replace your boilers (6) or remove them for maintenance in Canada
(7) but it does not happen in the US.

Any competent electrician in the US (don't know about Canada where
electricians "molest" the wiring) can connect a boiler and avoid the
transmission of vibration. There are numerous flexible wiring methods
and our boilers are massive enough not to vibrate.

But if we imported a Canadian boiler that had enough vibration problem
that a flexible cord was need we couldn't connect it with a plug. Plugs
are covered in 410.7-B. Plugs are not permitted for (7) above.

That is consistent with the more limited 422.16 and with what RBM said.

Incidentally, if a receptacle was allowed it wouldn't be a duplex
receptacle which you suggested.

Correct. Code DOES say a "dedicated" outlet - which in it's strictest
interpretation is a single outlet.

Strictest? It is the interpretation that any competent electrician would
use.

Again - I DID later say I
recommended a 20 amp twist-lock - and every one of THOSE I have run
across recently IS a single outlet.

You could also read the comments of gfretwell who basically says it is
(a minor) wrong but he would do it anyway. (Is it any wonder our youth
are in trouble. Where are the role models...)

There is no safety or logical resaon NOT to. I suspect it is a
carry-over from some reason that USED to exist.

Nothing has changed. Cord is tested primarily for flexibility. Tests of,
for instance, romex are much more extensive. Cord is not intended to be
a permanent wiring method and is not allowed "as a substitute for the
fixed wiring of a structure."

RBM provided a connection method that is code compliant. The same method
could be done cheaper if built from parts if you are doing it yourself.
The OP asked about having an electrician do it. An electrician is real
unlikely to wire a cord and plug unless they have cleared their method
with the AHJ. The AHJ is not available.

And in the US a 20A receptacle wired with #12 wire but on a 15A breaker
is a code violation.


This is the code:

Nec 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.

Nec handbook note: It should be understood that a cord-connected
appliance is required to be specifically designed mechanically and
electrically, to be readily removable for maintenance and repair.

This is the Clare interpretation of the code:

" If you have a "compliant coupling" on the ductwork to eliminate
vibration, the flexible cord is allowed under the code for the same
reason.. Immaterial that the rigid gas line passes vibration to the
house. No inspector can say FOR SURE that the cord is not there for
vibration reasons - and if it is allowed for that purpose there is no
SAFETY reason for denying it - hense the overlooking of the
"infraction" by so many inspectors."

REALY??? (ROFL) Note all the straw men inserted.