Switching GFCI devices

[RBM]

There's no reason that it shouldn't

[bud--]

I agree.

The NEC requires "switches shall be used within their ratings".

IMHO a 15A switch on 20A circuit with 20A or multiple 15A receptacles would be a violation.

-- bud--

[RBM]

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 installers

[bud--]

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 them anymore.

[RBM]

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

[Tom Horne]

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.

-- Tom Horne

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 following: (1) Resistive and inductive loads, including electric-discharge lamps, not exceeding the ampere rating of the switch at the voltage involved (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 voltage applied. (3) Tungsten-filament lamp loads not exceeding the ampere rating of the switch at the applied voltage if T-rated.

[Tom Horne]

Bud 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."

-- Tom Horne

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 circuits. (B) Power Panelboard. A power panelboard is one having 10 percent or fewer of its overcurrent devices protecting lighting and appliance branch circuits.

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 Whitney]

The notion of lighting and appliance panelboard has been removed from the 2008 NEC.

Cheers, Wayne

[bud--]

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 disconnect rule.

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?