Ungrounded Conductors From Same Circuit on Same Breaker?

[kwired]

Heavy sigh. I knew I was taking a risk by going abstract.

The similarity is not in the minutiae of the analogy, but in the end result, which is that the Code is a set of rules to apply to specific cases for a specific purpose, which is to reduce the risk of fire (and injury, of course). Yes, you can come up with a scenario which has details in common with conditions covered by a section of the Code, but that doesn't necessarily mean that the Code takes a position one way or the other on it. If it doesn't present a fire or safety hazard, the Code may be indifferent to it.

As to analogies in general, they are fables to illustrate a point, nothing more. One of my favorites is "rearranging deck furniture on the Titanic" to illustrate how focusing on minutiae can obscure one's view of the Big Picture. Does the validity of the analogy mean that one cannot imagine a scenario where a strategically placed deck chair might have influenced the outcome of that disaster? Of course not.

Sorry I disappointed you. An analogy involving lets say hydraulics or pneumatics and potential parallels would come a lot closer to the topic of discussion.

 

[kwired]

Just stopped by to see how this thread was doing, I think I will back on out of here ........... :lol:

I'm ready to go with you.

Plenty of food for thought has been brought up though.

That is part of what this forum is about isn't it?

 

[taylorp]

Let me see. After 182 posts here is what I think I have learned.

1. A "ring" circuit is not a parallel circuit according to the NEC.
2. A "ring" circuit is electrically parallel.
3. No electrician I know EVER wires branch circuits or feeder circuits in a "ring" configuration.
4. "Ring" circuits are commonly wired by "telephone" people who are attempting to wire power circuits. :dunce:
5. "Ring" circuits are common in Britain. (Europe?) :?
6. The NEC does not address "ring" circuits.
7. Since the NEC does not address "ring" circuits, then there are no rules for installing "ring" circuits.
8. There are no safety issues with "ring" circuits.
9. Parallel circuits are not defined in the NEC.
10. I am glad I don't know anyone who wires this way.

 

[ggunn]

Sorry I disappointed you. An analogy involving lets say hydraulics or pneumatics and potential parallels would come a lot closer to the topic of discussion.

You didn't disappoint me, really, it's just that I was talking about the way that systems of rules (the NEC being a system of rules) in general work, not anything specifically to do with physical circuits. I believe that that is the crux of the discussion, not whether a ring circuit is parallel in nature. No one has disputed that there are parallel current paths to loads on a ring circuit.

 

[ggunn]

Let me see. After 182 posts here is what I think I have learned.

1. A "ring" circuit is not a parallel circuit according to the NEC.

Not exactly. A ring circuit does not involve parallel conductors as narrowly defined by the NEC in 310.4(A). The NEC does not address specifically whether or not a ring circuit is a parallel circuit, although it certainly is; it doesn't mention ring circuits at all as far as I have seen.

ALL branch circuits are parallel; loads plugged into receptacles on the same circuit are fed in parallel. It matters not if each receptacle has its own home run to the breaker or if each receptacle is fed from a jumper from another up the line, it's still parallel. However, if you are going to consider the conductors which touch the ring at different points as "electrically joined at both ends" because of this, then so is every conductor between them, and so is every conductor between receptacles, even in a conventional branch circuit. Every conductor in a house would have to be 1/0 or bigger.

 

[kwired]

Not exactly. A ring circuit does not involve parallel conductors as narrowly defined by the NEC in 310.4(A). The NEC does not address specifically whether or not a ring circuit is a parallel circuit, although it certainly is; it doesn't mention ring circuits at all as far as I have seen.

That is what I was trying to say somewhere around post 10 or so.

If it is parallel but doesn't meet the requirements of 310.4(A) then it does not comply with that section. Then came the big debate of whether or not there is a parallel there. As far as I'm concerned there was no winner of the debate, just a lot of information provided to allow readers to decipher for themselves what they feel is the situation here.

 

[iwire]

Not exactly. A ring circuit does not involve parallel conductors as narrowly defined by the NEC in 310.4(A).

Now wait a minute, that is your opinion. Some of us do not see it that way.

 

[don_resqcapt19]

It doesn't matter unless you are on the 2011 code. Prior to that there was no real restriction on paralleling small conductors. Yes, that was the intent of 310.4 but that is not what the words said. Specifically permitting me to do something, in no way creates a prohibition on doing something else.

 

[iwire]

Stop trying to make sense.

 

[Little Bill]

Augie47, Where are You?

Augie47, Where are You?

Augie47 (Gus), we've heard from a lot of members on this. IF you were to inspect something like this "ring circuit". Hypothetically, of course, would you allow it? You may not want to commit to a real situation, but not committing to an actual allowance, what are your thoughts?

 

[ggunn]

Now wait a minute, that is your opinion. Some of us do not see it that way.

Of course. Every thing any of us says is his/her opinion.

But consider this: if the ends of the conductors that run from the breaker to the different points on the ring are "electrically joined at both ends", then so are *both* ends of every conductor between them. Likewise, so are both ends of every conductor between receptacles on a branch circuit that isn't a ring. By that interpretation, every conductor on a branch circuit is in parallel with every other conductor and therefore must be 1/0 or larger. After all, every branch circuit is a parallel circuit; every receptacle provides a parallel connection to whatever is plugged into it.