On Nov 13, 10:06*am, bud-- wrote:
wrote:
On Nov 12, 9:59 am, bud-- wrote:
wrote:
On Nov 11, 5:02 pm, David Nebenzahl wrote:
On 11/11/2010 1:49 PM David Nebenzahl spake thus:
So I can only conclude that the real reason one would use a 15-amp
instead of a 20-amp outlet on a 15-amp circuit would be prevent 20-amp
loads (with their special plugs) from being plugged in, right? On a
20-amp circuit, no reason to care about this.
Is this correct? It seems to come down almost to a visual thing: if you
don't see the T-slots, don't bother trying to plug in a 20-amp device.
Forgot to add this:
The upshot being:
o It's OK to put 15-amp receptacles on a 20-amp circuit
o It's *not* OK to put 20-amp receptacles on a 15-amp circuit
Right?
The exception being a SINGLE 20 amp receptacle is apparently allowed
on a 15 amp circuit. * You can find a thread here from a few weeks
back where we went back and forth on that at length. *The code says
for a single receptacle, the receptacle must have a rating at least
equal to that of the circuit.
Does it make any sense? * I'd say no and I sure would not wire a
receptacle that way.
210.21-B-1 allows that. It is a general permission, not specific to a 20
on a 15.

But a 20A receptacle on a 15A circuit is a violation of 406.3-A and can
be tagged. The rule for receptacles would be expected to be in the
article on receptacles, which is 406.

I'm surprised that you're now back to saying that the NEC clearly does
not allow a 20 amp receptacle on a 15 amp circuit. * As I recall, a
month ago, you provided us with the link to the actual discussion
among the writers of the NEC on that specific issue and it was clear
that they were saying that 210.21 B1 allows it and they made no
reference to 406 disallowing it. *Or did I miss something from back
then? * IMO, 406 isn't clear on that and while you could interpret it
that way, it's strange that the NEC code guys weren't talking about
it.

The thread was *"15A outlets on 20A circuits" which started 10-12.

I consistently said in that thread that 406.3-A prohibits a 20A
receptacle on a 15A circuit and could be used to tag the installation.
My last post was "as I said, IMHO a 20A receptacle on a 15A circuit can
be tagged under 403.6-A [should be 406.3-A]".

I did say that the code panel for 210 did not agree and that 210.21-B-1
allows it.

If I was an inspector I would argue (as I did above) that 210.21-B-1 is
a general provision but that 406.3-A is specific to 15A circuits. The
specific rule trumps the general rule. And the appropriate place to look
for the rule is in the article on receptacles, which is 406.

IMHO 406.3-A clearly prohibits a 20A receptacle on a 15A circuit. I
believe gfretwell agreed.

--
bud--
That is a stupid rule and a poor observance by the code enforcement
community.
A 20 amp receptacle on a 15 amp circuit endangers no one, as mentioned
the circuit breaker will detect any overload and trip, now a 15 amp
receptacle on 20 amp circuit is dangerous and will eventually brown
out.
Roy Q.T.
E.E.Technician