Individual branch Circuit?????

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Re: Individual branch Circuit?????

Bob,
Multiple 20 amp receptacles are not permitted on a 15 amp circuit. A duplex is two receptacles. See Table 210.21(B)(2).
Don
 
Re: Individual branch Circuit?????

My brain wasn't engaged this morning. I was thinking the other way around, which isn't the gist of the question at hand.

Sorry,

Bob
 
Re: Individual branch Circuit?????

Guys, an Idividual branch circuit by definition supplies one utilization equipment.this equipment has a 50 amp attachment plug.210.23 says "in no case shall the load exceed the branch circuit rating. An idividual branch circuit shall be permitted to supply any load for which it is rated". If the load attached to the 50 amp attachment plug were able to be served by a 15 amp circuit, why doesn't a 50 amp attachment plug fit into a 15 amp receptacle? I do not think there is a listed piece of equipment that has a "load"of 15 amps with a 50 amp attachment plug. 210.23 says IN NO CASE I think we all can recognize a case where a 50 amp rated receptacle served by a 15 amp circuit can be attached to a load in excess of the branch circuit rating(15amps).I maintain the 50 amp Rated receptacle is intended to serve a load in excess of 15 amps. I think 406.7 is also violated. 406.7 says "Noniterchangeability. Receptacles,cord connectors and attachment plugs shall be constructed such that receptacle or cord connectors do not accept an attachment plug with a different voltage or current rating from that for which the device is intended.However, a 20 T slot receptacle or cord connector shall be permitted to accept a 15 amp plug of the same voltage rating.This art. also supports my argument,You cannot wire a 50 amp receptacle on a 15 amp circuit, anymore than you can wire a 125 volt rated receptacle with 240 volts. The device is intended to serve a load for which it is rated in both amperes and voltage.
 
Re: Individual branch Circuit?????

Marc it does not matter what may be plugged into the outlet.

An overloaded circuit if properly wired is not dangerous.

Please think of a typical 20 amp branch circuit with 1/2 dozen 15 or 20 amp duplex receptacles tied on it.

I might plug a 10 amp toaster in one outlet, a 14 amp microwave in another outlet and my 5 amp coffee maker in another.

Thats 29 amps on my 20 amp circuit. :D

There is no code section to prevent this.

The only way to prevent that would be individual branch circuits for every single receptacle. :eek:

Check this out

90.1 Purpose.(B) Adequacy. This Code contains provisions that are considered necessary for safety. Compliance therewith and proper maintenance will result in an installation that is essentially free from hazard but not necessarily efficient, convenient, or adequate for good service or future expansion of electrical use.
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Marc here is another example where the code does not actually protect conductors from overload.

230.90(A)

Exception No. 3: Two to six circuit breakers or sets of fuses shall be permitted as the overcurrent device to provide the overload protection. The sum of the ratings of the circuit breakers or fuses shall be permitted to exceed the ampacity of the service conductors, provided the calculated load does not exceed the ampacity of the service conductors.
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The only thing that protects the service conductors installed under this exception is proper load calculations and qualified people working on it.

Bob
 
Re: Individual branch Circuit?????

(iwire)
thanks for jumping in on this post.I had to keep reading until coming across a post that confirmed my thoughts. I agree with you that the OCPD and the NEC design the electrical system so that overloads cannot occur and create bigger problems. With that in mind the installation then becomes subject to 90.1 of the NEC.

Mike - Det. Mich. :D
 
Re: Individual branch Circuit?????

Look up the definition of individual branch circuit,Has anyone ever seen or heard of a piece of listed equipment with a 50 amp attachment plug that only needs 15 amps to operate.We are talking about individual branch circuits by definition they serve only one utilization equipment if the equipment has a 50 amp attachment plug how in Gods name do you guys think you can serve it with a 50 amp receptacle device and feed that, with 15 amps. a 50amp rated receptacle device has a permissible load rating of 50 amps and in no case shall the load be greater than the rating of the branch circuit(213.23) !!!!!!!
 
Re: Individual branch Circuit?????

Cram, I've got the answer, :D

Roger
 
Re: Individual branch Circuit?????

Marc,
I never said that the 15A circuit could support a 50A load. I only said that 210.21(B)(1) permits the installation of the 50A receptacle on the 15 amp branch circuit. I also don't expect to find a 50A cord cap on manufactured or listed equipment that only needs 15 amps. There could be any number of reasons why a 50 amp cord cap would be field installed on equipment that only needs 15 amps. You could also have multifunction equipment that requires 50 amps when using all of the functions, but only 15 amps when using a single function. Would this be a practical or normal installation? Of course not, but it is still my opinion that it is permitted by the NEC.
Don
 
Re: Individual branch Circuit?????

For the last time don, I promise, a receptacle is not what is served by an individual branch it is the "load" A 50 amp receptacle has a permissible load rating of 50 amps it is not allowed and there is no words in the code book to support your argument which is based on words that are not there.210.21(B) 1, Is a statement, it shall not be less, does not mean it can be anything greater.The rating of a branch circuit shall not be less than the the load. In no case shall the load exceed the branch circuit ampere rating.A50 amp receptacle is permitted to have a load of 50 amps. An idividual branch shall be permitted to supply any load for which it is rated. your saying it can supply one for which it is not, by the use of the receptacle. this is not allowed,Good bye .
 
Re: Individual branch Circuit?????

And now for something we hope you'll really like:

Hey Rocky, want to see me pull a rabbit out of my hat?

Again?

Nothin up my sleeve, Presto!
 
Re: Individual branch Circuit?????

I?ve stayed away from this one long enough. I think I see where the mis-communication (for so I think this is) comes from. Marc: You need to remove the following statement from your pattern of logical reasoning, after which your argument will fall apart:
Originally posted by cram: A 50 amp receptacle is permitted to have a load of 50 amps.
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This represents invalid logical reasoning. That is because you have used a word in two different contexts, in two different statements, within the same argument. What the NEC ?permits? in one context. What the manufacturer ?permits,? meaning the component?s published ratings, is another context.

Point in fact, the NEC does not ?permit? a 50 amp receptacle to carry 50 amps. What I mean is that you will not find in the NEC a statement to the effect that if anyone sees a 50 amp receptacle, then that person is ?permitted? to connect 50 amps worth of load to that receptacle. The NEC is (rightfully) silent with regard to the way the user uses the equipment. Once again, point in fact, the NEC is not addressed to, and does not govern, the user.

So if you have a 20 amp branch circuit (defined as having a 20 amp breaker), and if there is a 50 amp receptacle, the NEC does not ?permit? the connection of 50 amps of load. Rather, the NEC forbids the connection of over 16 amps of load (i.e., 80%, per 210.23(A)(1)). You are right to be concerned that the user might try to connect more load. For this reason, I would call it a bad design. But it is not a code violation.

Originally posted by cram: . . . a statement, it shall not be less, does not mean it can be anything greater.
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Yes it does. Absolutely yes it does.
 
Re: Individual branch Circuit?????

Marc,
it shall not be less, does not mean it can be anything greater
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Can you tell me what those words mean? What about the use of the same words in this code section?
230.42 Minimum Size and Rating.
(A) General. The ampacity of the service-entrance conductors before the application of any adjustment or correction factors shall not be less than either (1) or (2). ...
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So we can't use service conductors that have an ampacity larger than the load?????
Don
 
Re: Individual branch Circuit?????

Great post Charlie. I think that really explains it.

Table 210.21(B)(3) specifically allows a 50A receptacle on a 40A circuit, which goes against the argument you can't have a receptacle larger than the branch circuit rating.
 
Re: Individual branch Circuit?????

CAW! CAW ! Damn, the humble crow pie tastes like $#!&, Charlie does the same apply to voltage ratings as well? To everyone else sorry if I offended.NO malice intended, this site is a great forum for discussions such as these.
 
Re: Individual branch Circuit?????

Originally posted by cram:Charlie does the same apply to voltage ratings as well?
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Yes. The voltage rating of a conductor (or any other component) is based on the ability of its insulation system to prevent leakage currents (i.e., from the conductor to the outside world). What is required is that every conductor (and every other conductor) have a voltage rating that is at least as high as the voltage that will be imposed upon it. It can have a higher voltage rating than the applied voltage, but not lower.

Reference: 110.4.
 
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