Ungrounded Conductors From Same Circuit on Same Breaker?

[Barndog]

I see this discussion continues unabated, and it still revolves around an irrelevant concept. Pick any two wires in the entire circuit. Then ask if those two wires are attached to each other at one end. If yes, then ask if those two wires are also attached to each other at the other end. If yes, then and only then do you have two wires in parallel with each other. That is not the case for any two wires in this circuit. In all cases, two wires may be attached to each other at one end, but one wire will continue downstream to the next outlet, and the other wire continues upstream to the previous outlet. That is not, Not, NOT a parallel circuit. All discussions about the rules for parallel conductors are meaningless in this circuit.

those wires are connected on both sides on is attached to the breaker and the other to the recpt. they have differant routes but will make it to the same device. so they are paralleled. If you would plug in a toaster to that outlet you would see that the current would flow through both sets of wire and if you were to disconnect one set then all the current would go through the one set. to me that is a parallel. The one differance is that both sets have an ampacity equal to or greater than the breaker.

 

[ggunn]

those wires are connected on both sides on is attached to the breaker and the other to the recpt. they have differant routes but will make it to the same device. so they are paralleled. If you would plug in a toaster to that outlet you would see that the current would flow through both sets of wire and if you were to disconnect one set then all the current would go through the one set. to me that is a parallel. The one differance is that both sets have an ampacity equal to or greater than the breaker.

I don't think it's relevant whether or not it's absolutely topologically parallel, but whether it is parallel within the narrower definition of parallel conductors as recognized by the NEC. IMO it's yes to the first and no to the second.

 

[Barndog]

I don't think it's relevant whether or not it's absolutely topologically parallel, but whether it is parallel within the narrower definition of parallel conductors as recognized by the NEC. IMO it's yes to the first and no to the second.

yes its not according the definiton of the NEC because its not 1/0 or larger but the wires are in Parallel.

 

[david luchini]

those wires are connected on both sides on is attached to the breaker and the other to the recpt. they have differant routes but will make it to the same device. so they are paralleled. If you would plug in a toaster to that outlet you would see that the current would flow through both sets of wire and if you were to disconnect one set then all the current would go through the one set. to me that is a parallel. The one differance is that both sets have an ampacity equal to or greater than the breaker.

The definition of paralleled conductors does say anything about providing different routes to the same device. The definition of paralleled conductors says they are "electrically joined at both ends."

If you connect two wires to the same breaker and run them to the same receptacle, they are parallel. (They are electrically joined at both ends.)

If you connect two wires to the same breaker and run them to two different receptacles, and run another wire between the two receptacles, they are not "electrically joined at both ends" and are therefore not parallel conductors.

yes its not according the definiton of the NEC because its not 1/0 or larger but the wires are in Parallel.

The definition of paralleled has nothing to do with the size of the conductor. In fact, the NEC allows paralleling of smaller than 1/0 in specific instances.

 

[Barndog]

The definition of paralleled conductors does say anything about providing different routes to the same device. The definition of paralleled conductors says they are "electrically joined at both ends."

If you connect two wires to the same breaker and run them to the same receptacle, they are parallel. (They are electrically joined at both ends.)

If you connect two wires to the same breaker and run them to two different receptacles, and run another wire between the two receptacles, they are not "electrically joined at both ends" and are therefore not parallel conductors.



The definition of paralleled has nothing to do with the size of the conductor. In fact, the NEC allows paralleling of smaller than 1/0 in specific instances.

I did not know that i was always under the assumtion that they had to be 1/0 or larger.

 

[cowboyjwc]

This is a common install with plumbers especially with sprinkler systems, for the same reason the the electrician gave, same pressure at the last head as at the first head.

 

[roger]

those wires are connected on both sides on is attached to the breaker and the other to the recpt. they have differant routes but will make it to the same device. so they are paralleled.

So if we apply that logic to you and I both going to NYC and arriving at the same time, all the roads we took, even though they are spread out accross the country in a number of different states are actually parallel with each other.

IOW's, all highways across this country are parallel to one another.

Roger

 

[charlie b]

Those wires are connected on both sides. One is attached to the breaker and the other to the recpt. They have different routes but will make it to the same device. So they are paralleled.

Sorry, but this is not true. They may make it to the same point, but they will be going through other wires along the way. So they are not in parallel with each other, but are rather in series.

The definition of paralleled conductors does say anything about providing different routes to the same device. The definition of paralleled conductors says they are "electrically joined at both ends."

Agreed.

If you connect two wires to the same breaker and run them to the same receptacle, they are parallel. (They are electrically joined at both ends.)

Again, I agree.

If you connect two wires to the same breaker and run them to two different receptacles, and run another wire between the two receptacles, they are not "electrically joined at both ends" and are therefore not parallel conductors.

That is exactly what I have been saying. Thank you for expressing it in another, and perhaps clearer, way.

 

[hurk27]

The definition of paralleled conductors does say anything about providing different routes to the same device. The definition of paralleled conductors says they are "electrically joined at both ends."

Agree and stated the same back in post 27

If you connect two wires to the same breaker and run them to the same receptacle, they are parallel. (They are electrically joined at both ends.)

exactly, and remember each receptacle will have two outlets on each strap with a link on the terminals between each receptacle making them in parallel, those links are just like a set of wires to the next receptacle in a ring circuit.

If you connect two wires to the same breaker and run them to two different receptacles, and run another wire between the two receptacles, they are not "electrically joined at both ends" and are therefore not parallel conductors.

Here's where you get in trouble, anytime you run wire "inbetween" two devices you have just paralleled them, several receptacle receptacles or lights on a circuit are even called a parallel wired load, anytime a load or several paralleled wired loads have two paths (hot and neutral) back to source from its point of connection on the circuit it is paralleled fed.

take two 12 volt batteries and hook + to + and - to - is that nor a parallel circuit now run to two 12 volt loads now connect a + and - between the loads and you have just paralleled the loads to the batteries.

The definition of paralleled has nothing to do with the size of the conductor. In fact, the NEC allows paralleling of smaller than 1/0 in specific instances.

Agreed

 

[charlie b]

Here's where you get in trouble, anytime you run wire "in between" two devices you have just paralleled them

The debate here has nothing to do with paralleling devices. The issue at hand is paralleling conductors. If wire 1 goes from breaker to outlet 1, and wire 2 goes from same breaker to outlet 2, and wire 3 goes from outlet 1 to outlet 2, then wire 1 and wire 2 are not in parallel with each other.

 

[ggunn]

The debate here has nothing to do with paralleling devices. The issue at hand is paralleling conductors. If wire 1 goes from breaker to outlet 1, and wire 2 goes from same breaker to outlet 2, and wire 3 goes from outlet 1 to outlet 2, then wire 1 and wire 2 are not in parallel with each other.

Is this about Code or about semantics? On another thread a disagreement was characterized by someone as one faction saying "the sky is blue" and the other saying "no, the grass is green".

There is no doubt that from a circuit topology perspective, every load on the ring sees two electrically parallel connections back to the source. Everything else on the ring is connected in parallel, so there are no series connections anywhere.

But from a Code perspective, parallel wires are connected at both ends, which just as clearly is not the case here. I am working on a job where we will likely run two sets of 400kcmil conductors instead of a single set of 800kcmil conductors as our voltage drop calculations call for because none of us want to try to pull four 800kcmil conductors through 400' of conduit with several bends in it. That's the kind of situation the Code is talking about and allows.

 

[hurk27]

The debate here has nothing to do with paralleling devices. The issue at hand is paralleling conductors. If wire 1 goes from breaker to outlet 1, and wire 2 goes from same breaker to outlet 2, and wire 3 goes from outlet 1 to outlet 2, then wire 1 and wire 2 are not in parallel with each other.

Ok then I'm totally not understanding why 310.4 says "(electrically joined at both ends to form a single conductor). when it could have said "(physically joined at both ends to form a single conductor).

to me the conductors are "(electrically joined at both ends to form a single conductor). they just take different paths back to the breaker?

 

[ggunn]

Ok then I'm totally not understanding why 310.4 says "(electrically joined at both ends to form a single conductor). when it could have said "(physically joined at both ends to form a single conductor).

to me the conductors are "(electrically joined at both ends to form a single conductor). they just take different paths back to the breaker?

This reminds me of the time I played British rules croquet with a bunch of law school students, beers in hand. Every so often, play would stop, rule books would come out, and arguments would ensue over the meaning of the word "ball". ;^)

But clearly, the conductor from the breaker to the outlet at one end and the conductor from the breaker to the outlet at the other end cannot be considered to be "a single conductor" no matter how you look at it.

 

[charlie b]

Ok then I'm totally not understanding why 310.4 says "(electrically joined at both ends to form a single conductor). when it could have said "(physically joined at both ends to form a single conductor).

Let me change the colors on you. 310.4 says "electrically joined at both ends to form a single conductor." In my post #50, wire 1 and wire 2 do not form a single conductor. They are joined at one end only. In a pair of parallel conductors, as current reaches one end of their connection, it splits, half of it going one way and half going the other way, and at the other end the current joins up again, and 100% proceeds from that point on down the line. As viewed from beyond their two ends, the two parallel wires act as though they were a single conductor. But if current splits at the point of connection of two wires, and 100% of it does not make it to the other point of connection without passing through another wire or through some outlet device (i.e., there are other paths the current can take, other than just the two wires), then the two wires are not in parallel.

Why, by the way, do I belabor this point? Because some are calling this installation a violation of the rules for paralleling conductors. My point is that that rule does not apply, as the wires are not in parallel

 

[S'mise]

I didn't agree and still don't.

Roger

Same here

 

[kwired]

If you connect two wires to the same breaker and run them to two different receptacles, and run another wire between the two receptacles, they are not "electrically joined at both ends" and are therefore not parallel conductors.

So since they are not electrically joined at both ends you should be able to disconnect both of them from the breaker and connect an ohmmeter to each one and read infinity right:happysad:.

I have been trying to say this ever since I opened the can of worms about this being paralleling of conductors. There is a difference between any parallel connection and what NEC allows us to use as parallel conductors. There is more to the rules than just being electrically joined at each end. Conductors also have to be same type material, size, length, run through same type raceway or cable, etc., and almost always need to be 1/0 AWG or larger.

If you have multiple paths in a circuit for current to flow that eventually meet up again you have a parallel path, the number of connections in the path does not change this fact. Current will divide between the paths. NEC wants similar conditions for all paths to equalize impedance of all paths so current is evenly divided.

 

[Electron_Sam78]

Here's a picture of the circuit in question - the way I see it.

 

[ggunn]

So since they are not electrically joined at both ends you should be able to disconnect both of them from the breaker and connect an ohmmeter to each one and read infinity right:happysad:.

I have been trying to say this ever since I opened the can of worms about this being paralleling of conductors. There is a difference between any parallel connection and what NEC allows us to use as parallel conductors. There is more to the rules than just being electrically joined at each end. Conductors also have to be same type material, size, length, run through same type raceway or cable, etc., and almost always need to be 1/0 AWG or larger.

If you have multiple paths in a circuit for current to flow that eventually meet up again you have a parallel path, the number of connections in the path does not change this fact. Current will divide between the paths. NEC wants similar conditions for all paths to equalize impedance of all paths so current is evenly divided.

I have enough trouble deciphering what the NEC says, not to mention what it wants. The section on paralleling conductors clearly addresses lowering resistance and/or making conduit pulls easier by allowing parallel runs of 1/0 or larger wire which are connected at both ends to make two conductors into a single one. This "ring" strategy of hooking up outlets in a house is far removed from that situation, IMO, and is neither allowed or disallowed by the referenced section of the Code.

 

[ggunn]

Here's a picture of the circuit in question - the way I see it.

What are the circles? What if there are an even number of connections? Does it make any difference if anything is plugged into any of the outlets? Is the length of the wires a consideration?

This is all well and good, but unless the conductors to the breaker both connect to the same outlet, this section of the Code does not address it.

 

[cowboyjwc]

Here's a picture of the circuit in question - the way I see it.

Your picture doesn't show up in the quote, but suppose you just looped the wire around the screws from the breaker and then back to the breaker, then isn't it just one wire and not parralleled?