Actually not a dumb question, as I trust you'll see.

Reading through the thread above about using 15-amp outlets on a 20-amp
kitchen circuit, and even following the discussion to an external forum
(Mike Holt's) raises this question in my mind: why do we have outlets in
both ampacity ratings?

From what I gather from the Holt forum, which included much
back-and-forth about UL ratings (and an actual email response from UL
itself), both 15- and 20-amp outlets are capable of handling 20 amps,
both through the receptacle blades and through the pass-through between
the sets of screw terminals. So it's not an issue of overloading the
device itself. A 15-amp outlet will work fine on a 20-amp circuit with a
20-amp load.

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.

[Of course this only applies to North America and places with
similar-type electricity: dunno how this all plays out in the UK, for
instance.]


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

David Nebenzahl wrote:
....

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.
....

Should one not say "obviously"????

--

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 fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

"David Nebenzahl" wrote in message
.com...
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?


That is correct regarding multiple outlets on a branch circuit

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.

On 11/11/2010 3:58 PM spake thus:

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.

Riiight, the exception to the rule. Ugh.

Does it make any sense? I'd say no and I sure would not wire a
receptacle that way.

I'm with you there.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

Are you asking what is reasonable practice, or what would be safe?

If everything else is to code on a 15 amp circuit, it should have a 15
amp fuse/breaker and everything downstream should be able to handle at
least that much. So, even if you plug a 50 amp load into the outlet,
it SHOULD pop the breaker/fuse before anything really bad happens. The
question is, how much faith do you have that everything other than the
outlet is correct and in good shape.

Not that you can't start a fire with 15 amps...

On Nov 11, 6:58*pm, 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.

If you keep reading from there you will find that the maximum
receptacle size on each circuit is laid out in Table 210-21(b)(3).

Table 210-21(b)(3). Receptacle Ratings for Various Size Circuits

Circuit Rating (Amperes) Receptacle Rating (Amperes)
15 Not over 15
20 15 or 20
30 30
40 40 or 50
50 50

--
Tom Horne

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.

There remains a hole - you can install a single (not a duplex) 20A
non-grounding receptacle on a 15A circuit that has no ground if it is
the only receptacle on the circuit. Rather limited application. And you
would have to find a single 20A receptacle without a ground.

--
bud--

Tom Horne wrote:
On Nov 11, 6:58 pm, 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.

If you keep reading from there you will find that the maximum
receptacle size on each circuit is laid out in Table 210-21(b)(3).

Table 210-21(b)(3). Receptacle Ratings for Various Size Circuits

Circuit Rating (Amperes) Receptacle Rating (Amperes)
15 Not over 15
20 15 or 20
30 30
40 40 or 50
50 50

--
Tom Horne

210.21-B-3 is "two or more receptacles".

210.21-B-1 is a *single* receptacle on the circuit, and allows a single
20A (or 40A...) receptacle on a 15A circuit. [It also disallows a single
15A receptacle on a 20A circuit.]

When I first read this a few years ago it was hard to believe. IMHO
210.21-B-1 should be rewritten. In response to a proposal to do that the
code panel said that they don't have a problem with a single 20A
receptacle on a 15A circuit.

But it is a violation of 406.3-A.

--
bud--

--
bud--

On Thu, 11 Nov 2010 13:49:34 -0800, David Nebenzahl wrote:
[Of course this only applies to North America and places with
similar-type electricity: dunno how this all plays out in the UK, for
instance.]

The plugs are always fused in the UK, and of course domestic AC is always
240V, so there's largely no need to mess around with different outlet
styles (there are some different plug and outlet types for very high
draws, but those aren't generally seen in home situations, and things
like electric stoves are normally hard-wired into a wall plate). Plug
fuses there are usually 13A maximum, and if I remember right the maximum
current draw on the ring circuit is around 30A.

I rather miss UK electrical installs - it's nice having 240V everywhere,
and the components are generally to a much higher standard than in the
US. The downside is that UK plugs are pretty huge, which creates issues
for storage requirements (particularly for things like chargers for
portable devices)

cheers

Jules

On 11/12/2010 8:10 AM Jules Richardson spake thus:

The plugs are always fused in the UK, and of course domestic AC is always
240V, so there's largely no need to mess around with different outlet
styles (there are some different plug and outlet types for very high
draws, but those aren't generally seen in home situations, and things
like electric stoves are normally hard-wired into a wall plate). Plug
fuses there are usually 13A maximum, and if I remember right the maximum
current draw on the ring circuit is around 30A.

So how does that work? What form factor are the fuses--glass tubes?
cartridges? Easy to see if they're blown and replace them?


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

On Fri, 12 Nov 2010 09:53:10 -0800, David Nebenzahl wrote:

On 11/12/2010 8:10 AM Jules Richardson spake thus:

The plugs are always fused in the UK, and of course domestic AC is
always 240V, so there's largely no need to mess around with different
outlet styles (there are some different plug and outlet types for very
high draws, but those aren't generally seen in home situations, and
things like electric stoves are normally hard-wired into a wall plate).
Plug fuses there are usually 13A maximum, and if I remember right the
maximum current draw on the ring circuit is around 30A.

So how does that work? What form factor are the fuses--glass tubes?
cartridges? Easy to see if they're blown and replace them?

They're ceramic bodies I think - they're not transparent, so you can't
obviously see if they've blown without checking them with a meter.
They're about 1" in length and 1.4" in diameter (maybe exactly, but I'm
going from memory).

cheers

Jules

On 11/12/2010 11:09 AM Jules Richardson spake thus:

On Fri, 12 Nov 2010 09:53:10 -0800, David Nebenzahl wrote:

On 11/12/2010 8:10 AM Jules Richardson spake thus:

The plugs are always fused in the UK, and of course domestic AC is
always 240V, so there's largely no need to mess around with different
outlet styles (there are some different plug and outlet types for very
high draws, but those aren't generally seen in home situations, and
things like electric stoves are normally hard-wired into a wall plate).
Plug fuses there are usually 13A maximum, and if I remember right the
maximum current draw on the ring circuit is around 30A.

So how does that work? What form factor are the fuses--glass tubes?
cartridges? Easy to see if they're blown and replace them?

They're ceramic bodies I think - they're not transparent, so you can't
obviously see if they've blown without checking them with a meter.
They're about 1" in length and 1.4" in diameter (maybe exactly, but I'm
going from memory).

So the plugs must be huge. Yuck. Glad I live on this side of the pond
(at least regarding electrical plugs).


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

On 11/12/2010 2:42 PM, David Nebenzahl wrote:
On 11/12/2010 11:09 AM Jules Richardson spake thus:

On Fri, 12 Nov 2010 09:53:10 -0800, David Nebenzahl wrote:

On 11/12/2010 8:10 AM Jules Richardson spake thus:

The plugs are always fused in the UK, and of course domestic AC is
always 240V, so there's largely no need to mess around with different
outlet styles (there are some different plug and outlet types for very
high draws, but those aren't generally seen in home situations, and
things like electric stoves are normally hard-wired into a wall plate).
Plug fuses there are usually 13A maximum, and if I remember right the
maximum current draw on the ring circuit is around 30A.

So how does that work? What form factor are the fuses--glass tubes?
cartridges? Easy to see if they're blown and replace them?

They're ceramic bodies I think - they're not transparent, so you can't
obviously see if they've blown without checking them with a meter.
They're about 1" in length and 1.4" in diameter (maybe exactly, but
I'm going from memory).

So the plugs must be huge. Yuck. Glad I live on this side of the pond
(at least regarding electrical plugs).


Back here in the US, I have an old Variac with a slightly large plug.
It holds two 1/4" glass fuses that pop out and are easy to check and
change. Pretty neat plug actually.

On 11/12/2010 4:52 PM, Tony Miklos wrote:
On 11/12/2010 2:42 PM, David Nebenzahl wrote:
On 11/12/2010 11:09 AM Jules Richardson spake thus:

On Fri, 12 Nov 2010 09:53:10 -0800, David Nebenzahl wrote:

On 11/12/2010 8:10 AM Jules Richardson spake thus:

The plugs are always fused in the UK, and of course domestic AC is
always 240V, so there's largely no need to mess around with different
outlet styles (there are some different plug and outlet types for very
high draws, but those aren't generally seen in home situations, and
things like electric stoves are normally hard-wired into a wall
plate).
Plug fuses there are usually 13A maximum, and if I remember right the
maximum current draw on the ring circuit is around 30A.

So how does that work? What form factor are the fuses--glass tubes?
cartridges? Easy to see if they're blown and replace them?

They're ceramic bodies I think - they're not transparent, so you can't
obviously see if they've blown without checking them with a meter.
They're about 1" in length and 1.4" in diameter (maybe exactly, but
I'm going from memory).

So the plugs must be huge. Yuck. Glad I live on this side of the pond
(at least regarding electrical plugs).


Back here in the US, I have an old Variac with a slightly large plug. It
holds two 1/4" glass fuses that pop out and are easy to check and
change. Pretty neat plug actually.


A lot of test equipment I've worked on has a socket, switch and fuse
like this:

http://homanndesigns.com/store/images/iec_power.jpg

The circuit breaker in the electrical panel protects the building
wiring not the equipment. The fuse in the power connector protects
the piece of equipment.

TDD

On 2010-11-12, Robert Green wrote:

Why would they allow you to use a 50A receptacle on a 40A circuit if
they don't allow that combo at lower amperages?

Because there are no 40A receptacles.

Wayne

"Wayne Whitney" wrote in message
...
On 2010-11-12, Robert Green wrote:

Why would they allow you to use a 50A receptacle on a 40A circuit if
they don't allow that combo at lower amperages?

Because there are no 40A receptacles.

Wayne

Did there used to be and the mention in the NEC is a grandfathering sort of
thing? What's the point of mentioning in the NEC something that doesn't
exist.

--
Bobby G.

On 11/12/2010 3:36 PM The Daring Dufas spake thus:

A lot of test equipment I've worked on has a socket, switch and fuse
like this:

http://homanndesigns.com/store/images/iec_power.jpg

The circuit breaker in the electrical panel protects the building
wiring not the equipment. The fuse in the power connector protects
the piece of equipment.

Heh; don't they say that in some electronic equipment a $5 transistor is
used to protect a 10-cent fuse?


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

On 11/12/2010 11:44 PM, David Nebenzahl wrote:
On 11/12/2010 3:36 PM The Daring Dufas spake thus:

A lot of test equipment I've worked on has a socket, switch and fuse
like this:

http://homanndesigns.com/store/images/iec_power.jpg

The circuit breaker in the electrical panel protects the building
wiring not the equipment. The fuse in the power connector protects
the piece of equipment.

Heh; don't they say that in some electronic equipment a $5 transistor is
used to protect a 10-cent fuse?



None that I've seen but there are some very poor design practices out
there. Many years ago I worked in TV shops (remember them?) and an old
fellow I worked with was always growling about the design engineers
who should be flogged for some of the crap they designed and how they
should be forced to work on it. 8-)

TDD

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.








There remains a hole - you can install a single (not a duplex) 20A
non-grounding receptacle on a 15A circuit that has no ground if it is
the only receptacle on the circuit. Rather limited application. And you
would have to find a single 20A receptacle without a ground.

--
bud--- Hide quoted text -

- Show quoted text -

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--

On 11/12/2010 6:36 PM, The Daring Dufas wrote:
On 11/12/2010 4:52 PM, Tony Miklos wrote:
On 11/12/2010 2:42 PM, David Nebenzahl wrote:
On 11/12/2010 11:09 AM Jules Richardson spake thus:

On Fri, 12 Nov 2010 09:53:10 -0800, David Nebenzahl wrote:

On 11/12/2010 8:10 AM Jules Richardson spake thus:

The plugs are always fused in the UK, and of course domestic AC is
always 240V, so there's largely no need to mess around with different
outlet styles (there are some different plug and outlet types for
very
high draws, but those aren't generally seen in home situations, and
things like electric stoves are normally hard-wired into a wall
plate).
Plug fuses there are usually 13A maximum, and if I remember right the
maximum current draw on the ring circuit is around 30A.

So how does that work? What form factor are the fuses--glass tubes?
cartridges? Easy to see if they're blown and replace them?

They're ceramic bodies I think - they're not transparent, so you can't
obviously see if they've blown without checking them with a meter.
They're about 1" in length and 1.4" in diameter (maybe exactly, but
I'm going from memory).

So the plugs must be huge. Yuck. Glad I live on this side of the pond
(at least regarding electrical plugs).


Back here in the US, I have an old Variac with a slightly large plug. It
holds two 1/4" glass fuses that pop out and are easy to check and
change. Pretty neat plug actually.


A lot of test equipment I've worked on has a socket, switch and fuse
like this:

http://homanndesigns.com/store/images/iec_power.jpg

The circuit breaker in the electrical panel protects the building
wiring not the equipment. The fuse in the power connector protects
the piece of equipment.

TDD

Well yes, but the Variac I use is about 50+ years old. Someone probably
added the hot and neutral fused plug because it also has a fuse built
into the case, and a switch of course.

On Nov 11, 4:49*pm, David Nebenzahl wrote:
Actually not a dumb question, as I trust you'll see.

Reading through the thread above about using 15-amp outlets on a 20-amp
kitchen circuit, and even following the discussion to an external forum
(Mike Holt's) raises this question in my mind: why do we have outlets in
both ampacity ratings?

*From what I gather from the Holt forum, which included much
back-and-forth about UL ratings (and an actual email response from UL
itself), both 15- and 20-amp outlets are capable of handling 20 amps,
both through the receptacle blades and through the pass-through between
the sets of screw terminals. So it's not an issue of overloading the
device itself. A 15-amp outlet will work fine on a 20-amp circuit with a
20-amp load.

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.

[Of course this only applies to North America and places with
similar-type electricity: dunno how this all plays out in the UK, for
instance.]

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)
David, a 15 amp receptacle will brown out and melt if you plug
anything more than it is rated for, a 20 amp outlet is stronger and
will withhold overusage better..it is best to measure or calculate the
amperage of the machine/s you will be plugging into it and if you plan
to have a constant load plugged onto it permanent rate it properly.
I have see this many times, specially on outlets where extension cords
wth multiple appliances floor lamps display cases and stuff plugged in
to them..They Brown Out and melt.
Roy Q.T.
E.E.Technician

On Sat, 13 Nov 2010 01:07:11 -0600, The Daring Dufas
wrote:

On 11/12/2010 11:44 PM, David Nebenzahl wrote:
On 11/12/2010 3:36 PM The Daring Dufas spake thus:

A lot of test equipment I've worked on has a socket, switch and fuse
like this:

http://homanndesigns.com/store/images/iec_power.jpg

The circuit breaker in the electrical panel protects the building
wiring not the equipment. The fuse in the power connector protects
the piece of equipment.

Heh; don't they say that in some electronic equipment a $5 transistor is
used to protect a 10-cent fuse?



None that I've seen but there are some very poor design practices out
there. Many years ago I worked in TV shops (remember them?) and an old
fellow I worked with was always growling about the design engineers
who should be flogged for some of the crap they designed and how they
should be forced to work on it. 8-)

Why? The reality is that they don't want *anyone* working on it. It's a
design requirement. ;-)

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

On Nov 13, 12:14*pm, Proteus wrote:
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

That's right it's me, I control my demons.
Roy

On 11/13/2010 11:16 AM, Proteus wrote:
On Nov 13, 12:14 pm, wrote:
On Nov 13, 10:06 am, wrote:



wrote:
On Nov 12, 9:59 am, wrote:
wrote:
On Nov 11, 5:02 pm, David 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

That's right it's me, I control my demons.
Roy

At least you're not YELLING! 8-0

TDD

On 11/13/2010 9:41 AM, Tony Miklos wrote:
On 11/12/2010 6:36 PM, The Daring Dufas wrote:
On 11/12/2010 4:52 PM, Tony Miklos wrote:
On 11/12/2010 2:42 PM, David Nebenzahl wrote:
On 11/12/2010 11:09 AM Jules Richardson spake thus:

On Fri, 12 Nov 2010 09:53:10 -0800, David Nebenzahl wrote:

On 11/12/2010 8:10 AM Jules Richardson spake thus:

The plugs are always fused in the UK, and of course domestic AC is
always 240V, so there's largely no need to mess around with
different
outlet styles (there are some different plug and outlet types for
very
high draws, but those aren't generally seen in home situations, and
things like electric stoves are normally hard-wired into a wall
plate).
Plug fuses there are usually 13A maximum, and if I remember right
the
maximum current draw on the ring circuit is around 30A.

So how does that work? What form factor are the fuses--glass tubes?
cartridges? Easy to see if they're blown and replace them?

They're ceramic bodies I think - they're not transparent, so you can't
obviously see if they've blown without checking them with a meter.
They're about 1" in length and 1.4" in diameter (maybe exactly, but
I'm going from memory).

So the plugs must be huge. Yuck. Glad I live on this side of the pond
(at least regarding electrical plugs).


Back here in the US, I have an old Variac with a slightly large plug. It
holds two 1/4" glass fuses that pop out and are easy to check and
change. Pretty neat plug actually.


A lot of test equipment I've worked on has a socket, switch and fuse
like this:

http://homanndesigns.com/store/images/iec_power.jpg

The circuit breaker in the electrical panel protects the building
wiring not the equipment. The fuse in the power connector protects
the piece of equipment.

TDD

Well yes, but the Variac I use is about 50+ years old. Someone probably
added the hot and neutral fused plug because it also has a fuse built
into the case, and a switch of course.

I've seen junk sit there and burn up without tripping the breaker in the
panel and this confuses a lot of folks. I have to explain the purpose of
the circuit breakers to them. Now I don't know if the newer arc fault
circuit breakers would trip under the same circumstances.

TDD

On Fri, 12 Nov 2010 11:42:50 -0800, David Nebenzahl wrote:
They're ceramic bodies I think - they're not transparent, so you can't
obviously see if they've blown without checking them with a meter.
They're about 1" in length and 1.4" in diameter (maybe exactly, but I'm
going from memory).

So the plugs must be huge. Yuck. Glad I live on this side of the pond
(at least regarding electrical plugs).

Yes, they are! Few things hurt more than stepping on one without shoes
on, too :-)

I have mixed feelings about them - yes, they're enormous, but they're
also very solid - the pins don't bend or get damaged like can happen with
US plugs, and the 'hot' pins are shielded at the tops so that the ground
always makes contact before the hot pins do (I've seen a lot of
situations where US plugs get pulled - or just fall due to wear - partway
out of outlets, exposing the pins)

All in all they're not too annoying I think, except in portable
situations or where you want lots of things plugged into a power strip.

cheers

Jules

"Proteus" wrote in message
...
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.

Respectfully disagree. As TTD point out, it's quite possible for the
circuit breaker to fail to operate for any number of reasons. In such cases
trying to pull 20A through 15A rated wiring is just asking for serious
trouble, IMHO.

--
Bobby G.

On Nov 13, 3:32*pm, The Daring Dufas
wrote:
On 11/13/2010 11:16 AM, Proteus wrote:





On Nov 13, 12:14 pm, *wrote:
On Nov 13, 10:06 am, *wrote:

wrote:
On Nov 12, 9:59 am, *wrote:
wrote:
On Nov 11, 5:02 pm, David *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

That's right it's me, I control my demons.
Roy

At least you're not YELLING! 8-0

TDD

At least you are not INSULTING! (cancelled due to rain)

ROY STEPPED OUT I GOT THIS NOW
HAVE A GREAT WEEKEND!
PATECUMSEH

On Nov 13, 3:37*pm, The Daring Dufas
wrote:
On 11/13/2010 9:41 AM, Tony Miklos wrote:





On 11/12/2010 6:36 PM, The Daring Dufas wrote:
On 11/12/2010 4:52 PM, Tony Miklos wrote:
On 11/12/2010 2:42 PM, David Nebenzahl wrote:
On 11/12/2010 11:09 AM Jules Richardson spake thus:

On Fri, 12 Nov 2010 09:53:10 -0800, David Nebenzahl wrote:

On 11/12/2010 8:10 AM Jules Richardson spake thus:

The plugs are always fused in the UK, and of course domestic AC is
always 240V, so there's largely no need to mess around with
different
outlet styles (there are some different plug and outlet types for
very
high draws, but those aren't generally seen in home situations, and
things like electric stoves are normally hard-wired into a wall
plate).
Plug fuses there are usually 13A maximum, and if I remember right
the
maximum current draw on the ring circuit is around 30A.

So how does that work? What form factor are the fuses--glass tubes?
cartridges? Easy to see if they're blown and replace them?

They're ceramic bodies I think - they're not transparent, so you can't
obviously see if they've blown without checking them with a meter.
They're about 1" in length and 1.4" in diameter (maybe exactly, but
I'm going from memory).

So the plugs must be huge. Yuck. Glad I live on this side of the pond
(at least regarding electrical plugs).

Back here in the US, I have an old Variac with a slightly large plug. It
holds two 1/4" glass fuses that pop out and are easy to check and
change. Pretty neat plug actually.

A lot of test equipment I've worked on has a socket, switch and fuse
like this:

http://homanndesigns.com/store/images/iec_power.jpg

The circuit breaker in the electrical panel protects the building
wiring not the equipment. The fuse in the power connector protects
the piece of equipment.

TDD

Well yes, but the Variac I use is about 50+ years old. Someone probably
added the hot and neutral fused plug because it also has a fuse built
into the case, and a switch of course.

I've seen junk sit there and burn up without tripping the breaker in the
panel and this confuses a lot of folks. I have to explain the purpose of
the circuit breakers to them. Now I don't know if the newer arc fault
circuit breakers would trip under the same circumstances.

TDD
It is what roy was trying to explain, the underrated receptacle will
not withstand the amperage, despite the breaker, because it burns
under the breakers protective current rating.
I hope when he comes back and sees this maybe he can explain it
better.

[Proteus is gone,
There just hasn't been anytime to close his account,
and frankly I like it so who knows]
Tecumseh
The Ghost in The Machine

On Nov 13, 5:02*pm, "Robert Green" wrote:
"Proteus" wrote in message

...
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.

Respectfully disagree. *As TTD point out, it's quite possible for the
circuit breaker to fail to operate for any number of reasons. *In such cases
trying to pull 20A through 15A rated wiring is just asking for serious
trouble, IMHO.

--
Bobby G.

Bobby G you will have to wait for Roy Qs response but I don't think
that is what he implied.
I am just around to collect some lost souls :/
Tecumseh
The Ghost in the Machine

On Sat, 13 Nov 2010 14:32:26 -0600, The Daring Dufas
wrote:

On 11/13/2010 11:16 AM, Proteus wrote:
On Nov 13, 12:14 pm, wrote:
On Nov 13, 10:06 am, wrote:



wrote:
On Nov 12, 9:59 am, wrote:
wrote:
On Nov 11, 5:02 pm, David 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

That's right it's me, I control my demons.
Roy

At least you're not YELLING! 8-0

Please don't feed the trolls.

On Nov 13, 5:02*pm, "Robert Green" wrote:
"Proteus" wrote in message

...
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.

Respectfully disagree. *As TTD point out, it's quite possible for the
circuit breaker to fail to operate for any number of reasons. *In such cases
trying to pull 20A through 15A rated wiring is just asking for serious
trouble, IMHO.

--
Bobby G.
You have the right to your opinion.
I don't think you'll find awg#14 on a household circuit designed for
outlets, which would be the only case where the wiring should not
exceed 15 amps., he most likely has 12awg which is rated for 20 amps
and safe to operate a 20A receptacle.

The rule is innaplicable in such case as I mentioned above, because
the outlet supersedes the protective circuits rating...not the
protection itself.

Don't believe the hype or any damn ghost stories.
Roy Q.T.

On Nov 13, 5:57*pm, "
wrote:
On Sat, 13 Nov 2010 14:32:26 -0600, The Daring Dufas





wrote:
On 11/13/2010 11:16 AM, Proteus wrote:
On Nov 13, 12:14 pm, *wrote:
On Nov 13, 10:06 am, *wrote:

wrote:
On Nov 12, 9:59 am, *wrote:
wrote:
On Nov 11, 5:02 pm, David *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.

On 11/13/2010 06:19 PM, Roy Quijano wrote:
On Nov 13, 5:02 pm, "Robert wrote:
wrote in message

...
On Nov 13, 10:06 am, wrote:



wrote:
On Nov 12, 9:59 am, wrote:
wrote:
On Nov 11, 5:02 pm, David 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.

Respectfully disagree. As TTD point out, it's quite possible for the
circuit breaker to fail to operate for any number of reasons. In such cases
trying to pull 20A through 15A rated wiring is just asking for serious
trouble, IMHO.

--
Bobby G.
You have the right to your opinion.
I don't think you'll find awg#14 on a household circuit designed for
outlets, which would be the only case where the wiring should not
exceed 15 amps., he most likely has 12awg which is rated for 20 amps
and safe to operate a 20A receptacle.

Huh? I can't remember ever living in a house which used anything BUT
14AWG for general recep ckts.

nate


--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On 11/13/2010 5:21 PM, Roy Quijano wrote:
On Nov 13, 5:57 pm, "
wrote:
On Sat, 13 Nov 2010 14:32:26 -0600, The Daring Dufas





wrote:
On 11/13/2010 11:16 AM, Proteus wrote:
On Nov 13, 12:14 pm, wrote:
On Nov 13, 10:06 am, wrote:

wrote:
On Nov 12, 9:59 am, wrote:
wrote:
On Nov 11, 5:02 pm, David 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

That's right it's me, I control my demons.
Roy

At least you're not YELLING! 8-0

Please don't feed the trolls.

Seems to me you just took one out to dinner.

You can watch a troll eat he

http://preview.tinyurl.com/2vdzx67

TDD

On Sat, 13 Nov 2010 15:21:11 -0800 (PST), Roy Quijano
wrote:

On Nov 13, 5:57*pm, "
wrote:
On Sat, 13 Nov 2010 14:32:26 -0600, The Daring Dufas





wrote:
On 11/13/2010 11:16 AM, Proteus wrote:
On Nov 13, 12:14 pm, *wrote:
On Nov 13, 10:06 am, *wrote:

wrote:
On Nov 12, 9:59 am, *wrote:
wrote:
On Nov 11, 5:02 pm, David *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

That's right it's me, I control my demons.
Roy

At least you're not YELLING! 8-0

Please don't feed the trolls.

Seems to me you just took one out to dinner.

No, Proteus, you're confusing me with your best friend, DimBulb. You're
confused a *lot*.