Because of a specific problem, I picked up a combination SPST switch and
GFCI single outlet with a "load" connection.
Anyway, the instructions clearly say that one should NOT use the switch to
control the input to the GFCI.
Why should that be a problem?
If you use the switch to cut power to the outlet, then you will also be
switching off everything down stream (connected to the "Load" side of the
device. You would need to be sure that the switch is rated for 15 or 20
amps depending on the rating of the circuit you are installing it on.
Where did he get that idea?
That one doesn't even pass the common-sense test. If a device is rated
for 15 amps, how is it OK to use it on a circuit drawing (potentially)
Now, I could see using a 15 amp switch on a 15-amp circuit (meaning one
connected to a 15 amp breaker) but wired with #12 wire. Is that what the
Found--the gene that causes belief in genetic determinism
Well, there seem to be some special rules for 15/20 amp stuff. For
example, a 15 amp outlet can "pass thru" juice to a 20 amp outlet. A 15
amp outlet can be on a 20 amp circuit.
I implied by error the conversation I had was recent. It actually took
place about 2 years ago. I had some switched outlets and I couldn't find
20 amp SPST switches. That's when he told me I could put 15 amp rated
switches on a 20 amp #12 wire circuit.
I am not a real expert on the subject but I do not see the problem. Very
few lights would even come close to requiring 15 A. A fixture containing
three 100 watt lamps requires less than three A on a 120 V power line
(neglecting inrush current). You can always screw things up by placing
an overload exceeding 20 even if had 20 A switches.
Electrical codes can be arbitrary, but I would be surprised if all parts
of a circuit must always be matched to each other.
Private Profit; Public Poop! Avoid collateral windfall!
We have a winner!! You can't put a single 15 amp outlet on a 20 amp
circuit, because the potential to overload it, and by the same logic, you
wouldn't put a 10 amp or 15 amp switch on a load greater than the switch
capacity, but you certainly can install a 15 amp switch on a bank of lights
that draws 10 amps, which is fed off of a 20 amp circuit.
Aren't we talking about a receptacle here? It may be intended for a
lamp, but that doesn't mean that's what will get plugged into it. If the
switch is 15A feeding a receptacle, I would at the very least split the
duplex so that only one side is controlled by the switch, otherwise
there is potential for a greater than 15A load.
This is one of the many NEC rules that make no sense to me. The same thing
with multiple disconnects on a service, the original installer may have
calculated the load, but who knows about any subsequent installations and
The way I read the thread I was agreeing with you. A 20A circuit with a
10A switch for a lighting fixture is OK because it is substantially
impossible to put over 1200W of lights in. Switching an outlet is more
of a problem.
Multiple service disconnects could certainly be a problem - they are a
lot safer if non-electricians leave them alone. IMHO most of the
potential problems are "split-bus" panels in a house. My reading of the
code is they are still allowed but I don't know if anyone even makes
I understand that, it is in switching an outlet that I have the concern. I
don't believe there is any rule to disallow a 15 amp switch on , say a
single duplex outlet in a bedroom, that's fed from a 20 amp circuit. While
it's unlikely that the switch would be overloaded, why not just require the
switch ampacity to match the circuit, instead of what's being switched
That's exactly what I'm talking about. I run into the damn things all the
time. You go to a house to install an outlet for a microwave, check the
panel, it's a split buss with a total of 250 amps worth of mains on #2 AL.
Then you have to do a load calculation of the whole house and make sure your
liability is paid up, before you add the one stupid outlet
They are effectively forbidden by the requirement that "Each lighting
and appliance branch-circuit panelboard shall be individually
protected on the supply side by not more than two main circuit
breakers or two sets of fuses having a combined rating not greater
than that of the panelboard."
408.14 Classification of Panelboards.
Panelboards shall be classified for the purposes of this article as
either lighting and appliance branch-circuit panelboards or power
panelboards, based on their content. A lighting and appliance branch
circuit is a branch circuit that has a connection to the neutral of
the panelboard and that has overcurrent protection of 30 amperes or
less in one or more conductors.
(A) Lighting and Appliance Branch-Circuit Panelboard. A lighting and
appliance branch-circuit panelboard is one having more than 10 percent
of its overcurrent devices protecting lighting and appliance branch
(B) Power Panelboard. A power panelboard is one having 10 percent or
fewer of its overcurrent devices protecting lighting and appliance
408.16 Overcurrent Protection.
(A) Lighting and Appliance Branch-Circuit Panelboard Individually
Protected. Each lighting and appliance branch-circuit panelboard shall
be individually protected on the supply side by not more than two main
circuit breakers or two sets of fuses having a combined rating not
greater than that of the panelboard.
Exception No. 1: Individual protection for a lighting and appliance
panelboard shall not be required if the panelboard feeder has
overcurrent protection not greater than the rating of the panelboard.
Wayne is right that "lighting and appliance panelboards" disappeared in
the 2008 NEC. You are quoting a NEC version before 2005 (but 2005
probably said the same thing, relocated).
The 2008 NEC also has the same requirements, I believe, as what you
quoted, with the 42 pole limit moved into the main article text, which
is 408.36 exception 2.
My reading is that you can have a split bus panel, but that there can
only be 2 main circuit breakers (instead of the previous 6). (One
breaker feeds the split bus in the rest of the panel and the 2nd breaker
can feed your flying saucer port on the roof.) The sum of the main
breaker ratings has to be not greater than the panelboard rating, but
there is nothing in this article that I see that prevents the 2 devices
from having a rating larger than the service wires using the 6
IMHO this is one of the articles where it would help to be a lawyer. (Or
maybe not.) You might have used a different lawyer?
Switches need only be adequate for the load that they control. It is
very common in US practice to use ten ampere switches on fifteen
ampere circuits and there is nothing wrong with that as long as the
load to be controlled does not exceed the rating of the switch.
Switches controlling receptacle outlets should never be less than the
rating of the circuit because the cord and plug connected load could
well be the entire ampacity of the circuit.
404.14 Rating and Use of Snap Switches.
Snap switches shall be used within their ratings and as indicated in
404.14(A) through (D).
(A) Alternating Current General-Use Snap Switch. A form of general-use
snap switch suitable only for use on ac circuits for controlling the
(1) Resistive and inductive loads, including electric-discharge lamps,
not exceeding the ampere rating of the switch at the voltage
(2) Tungsten-filament lamp loads not exceeding the ampere rating of
the switch at 120 volts
(3) Motor loads not exceeding 80 percent of the ampere rating of the
switch at its rated voltage
(B) Alternating-Current or Direct-Current General-Use Snap Switch. A
form of general-use snap switch suitable for use on either ac or dc
circuits for controlling the following:
(1) Resistive loads not exceeding the ampere rating of the switch at
the voltage applied.
(2) Inductive loads not exceeding 50 percent of the ampere rating of
the switch at the applied voltage. Switches rated in horsepower are
suitable for controlling motor loads within their rating at the
(3) Tungsten-filament lamp loads not exceeding the ampere rating of
the switch at the applied voltage if T-rated.
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