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Dennis Alwon

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I think this section allows it. As long as the load is not greater than their rating it should be good.

404.14 Rating and Use of Snap Switches. Snap switches
shall be used within their ratings and as indicated in
404.14(A) through (F).

(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 not exceeding the ampere
rating of the switch at the voltage applied
(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
 

iwire

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Hmmm....so 100 amp meter on a 200 amp service ok then? Maybe its just comes down to a 110.3(B) argument.....?

A meter is not a switch.

However a fused disconnect is a switch.

Can you imagine not being able to connect a 60 disconnect switch to a 200 amp feeder? That would change many standard practices.
 
A meter is not a switch.

Right but I think it comes down to the same issue. There is no explicit requirement about coordinating the rating of a meter socket with the load, OCPD ahead of it, or service size. Apparently there is no such requirement for a switch either. say you see someone use a 20 amp DPDT switch to switch between two 100 amp feeders. No code violation? Does the load have to be 20 amps or under?
 

GoldDigger

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But why does the NEC then forbid a #14 to a light when the circuit into the switch is #12 fused at 20amps?

Because the NEC explicitly requires that the OCPD protects the wires. It does not, however, have a general requirement that it protects any devices attached to/in the circuit.

The 100A fused disconnect on a 200A service is not the best example case since it incorporates its own OCPD and that OCPD protects both the disconnect itself and any downstream wiring. (Where a tap rule applies, it may also protect the upstream wiring.)
 

mbrooke

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Because the NEC explicitly requires that the OCPD protects the wires. It does not, however, have a general requirement that it protects any devices attached to/in the circuit.

The 100A fused disconnect on a 200A service is not the best example case since it incorporates its own OCPD and that OCPD protects both the disconnect itself and any downstream wiring. (Where a tap rule applies, it may also protect the upstream wiring.)

But heres my point, if the reason for all #12 on a 20amp circuit is in case down the road the wire is extended which might subject it to overload, then why not include the switch?
 
But heres my point, if the reason for all #12 on a 20amp circuit is in case down the road the wire is extended which might subject it to overload, then why not include the switch?

There are quite a few holes in the code in regards to protection of devices and equipment. Obviously some common equipment gets its own code article, motors, transformers, panelboards, etc, and specifically address protection of the equipment from overloads. But what if a device doesnt have a code article that addresses its installation, or it does but there is no mention of coordinating its rating with an OCPD or a load calculation? As I mentioned. meters are an example of this. Can I use a cold sequenced meter bank that has 800 amp busses on a 1200 amp service? In theses cases 110.3 A and B I think quite clearly cover such situations, however IMO it is still vague as to exactly how you "match" the equipments current rating to the system. For example, in my example do you go by the load calc? Actual current? OCPD rating ahead of it?
 
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