parrellel runs again

[billdozier]

Hey guys talking to one of the guys who is working on the commercial job with the parrellel runs this morning. He threw me a curve ball in saying that they had multiple sets of wires in the same conduit. My understanding of this statement is that from poco to the mdp they ran one conduit with two full sets of wires. Is that acceptable. To me it sounds like a major screwup on thier part. What article would address this. Ill try to post more info tomorrow thanks as always

 

[Dennis Alwon]

Hey guys talking to one of the guys who is working on the commercial job with the parrellel runs this morning. He threw me a curve ball in saying that they had multiple sets of wires in the same conduit. My understanding of this statement is that from poco to the mdp they ran one conduit with two full sets of wires. Is that acceptable. To me it sounds like a major screwup on thier part. What article would address this. Ill try to post more info tomorrow thanks as always

You can run multiple sets in one conduit but you must derate based on T 310.15(B)(2). Read art. 310.4

 

[raider1]

Is that acceptable

Yes, you are permitted to pull multiple sets of paralleled conductors in the same conduit.

But you will have adjust the ampacity in accordance with 310.15(B)(2)(a).

Here is a quote from the last sentnece of that section.

"Each current-carrying conductor of a paralleled set of conductors shall be counted as a current-carrying conductor."

Chris

 

[billdozier]

ok cool yeah we did the derate thing. Most of the larger commercial jobs I have been on ran 2-3 conduits and we pulled wire through each of them. I guess different strokes for different folks thanks again

 

[randys]

Paralleled Installations

Paralleled Installations

According to the 2008 NEC, 300.3 (B) (1) states that Conductors shall be permitted to be run in parallel in accordance with the provisions of 310.4. The requirement to run all circuit conductors within the same raceway, auxilliary gutter, cable tray, trench, cable, or cord SHALL APPLY SEPARATELY TO EACH PORTION of the paralleled installation, and the equipment grounding conductors shall comply with the provisions of 250.122. Parallel runs in cable tray shall comply with the provisions of 392.8 (D).

I hope this illustrates your point and the spotted violation of the code you mentioned here in your post.

Of course this is in a 2 or more electrical phase installation.

 

[Dennis Alwon]

According to the 2008 NEC, 300.3 (B) (1) states that Conductors shall be permitted to be run in parallel in accordance with the provisions of 310.4. The requirement to run all circuit conductors within the same raceway, auxilliary gutter, cable tray, trench, cable, or cord SHALL APPLY SEPARATELY TO EACH PORTION of the paralleled installation, and the equipment grounding conductors shall comply with the provisions of 250.122. Parallel runs in cable tray shall comply with the provisions of 392.8 (D).

I hope this illustrates your point and the spotted violation of the code you mentioned here in your post..

Randy are you saying that parallel runs in the same conduit is illegal?

 

[randys]

Illegal???

Illegal???

I believe the phrase "parallel installations" is exclusively for conductors carriyng different phases of electrical current. They should always be kept separate from each other whether they be in receptacles, cables, or raceways. The concerns for keeping them separate are induction between conductors, cancellation of phase voltages and currents due to proximity, and risks involved in miswiring the circuit or circuits.

In other than paralleled installations, a single conduit can carry many wires. These wires are not multiphase conductors.

 

[tom baker]

I believe the phrase "parallel installations" is exclusively for conductors carriyng different phases of electrical current. They should always be kept separate from each other whether they be in receptacles, cables, or raceways. The concerns for keeping them separate are induction between conductors, cancellation of phase voltages and currents due to proximity, and risks involved in miswiring the circuit or circuits.

Can you explain the above in terms of Section 300.3(B)?
"Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1) through (B)(4)."
Also in Section 300.5(I):
"Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors shall be installed in the same raceway or cable or shall be installed in close proximity in the same trench."

 

[raider1]

I believe the phrase "parallel installations" is exclusively for conductors carriyng different phases of electrical current. They should always be kept separate from each other whether they be in receptacles, cables, or raceways. The concerns for keeping them separate are induction between conductors, cancellation of phase voltages and currents due to proximity, and risks involved in miswiring the circuit or circuits.

In other than paralleled installations, a single conduit can carry many wires. These wires are not multiphase conductors.

I don't think you quite understand what paralleling of conductors is.

Take a look at 310.4.

Chris

 

[randys]

Conductors of the same circuit

Conductors of the same circuit

Ancora Imparo : In response to my thread

In 300.3 B, I believe the phrase "Conductors of the same circuit" are circuit conductors that are used in a complete circuit. Each complete circuit will be using one of the three possible phases or come from or deliver current to a separately derived system. This includes the equipment grounding conductor for the circuit and the bonding conductor for the circuit.

 

[raider1]

Each complete circuit will be using one of the three possible phases or come from or deliver current to a separately derived system.

A circuit can consist of 3 phase conductors, such as in a 3 phase 480 volt circuit.

Here is the definition of seperately derived system:

"Separately Derived System. A premises wiring system whose power is derived from a source of electric energy or equipment other than a service. Such systems have no direct electrical connection, including a solidly connected grounded circuit conductor, to supply conductors originating in another system."

This includes the equipment grounding conductor for the circuit and the bonding conductor for the circuit.

The equipment grounding conductor also performs bonding.

Chris

 

[randys]

Phase

Phase

To: Raider1

If you noticed, I also mentioned 310.4 because 300.3 made a reference to it. If you notice that 310.4 (A) General. Aluminum, copperclad aluminum, or coppoer conductors of size 1/0 and larger, comprising each PHASE, polarity, neutral, or grounded circuit conductor shall be permitted to be connected in parallel (electrically joined at both ends).

You try to rebut me with Articles from the code and I respect that but just because you are one of two moderators responding to my thread doesn't give you the right to misquote or misinterpret the code.

The term "parallel" here doesn't equal the phrase "parallel installation" in 300.3.
If you'll notice the phrase "comprising each phase" here is expected to be understood in parallel installations in 300.3.

Also your quote from the code here is about Service conductors from the meter to the main disconnect and it is not about branch conductors from the circuit disconnecting means to interior circuit within the building or occupancy. 300.3 illustrates branch circuit conductors with several phases being used in parallel installations.

By the way, it's okay to say I'm wrong but to prove I'm wrong with the code is a little more difficult. I am nobodys dummy load.

 

[charlie b]

Ancora Imparo : In response to my thread

I?m not sure that this is completely obvious, but that is not his member name, but rather a quotation he (Tom) has chosen to include in his signature line. It translates to, ?Still I am learning.?

In 300.3 B, I believe the phrase "Conductors of the same circuit" are circuit conductors that are used in a complete circuit.

That much is true.

Each complete circuit will be using one of the three possible phases . . . .

Not quite. A complete circuit includes all three phases, plus the neutral, plus the equipment grounding conductor (presuming the later two are used for this circuit).

The rule about having all conductors in the same raceway has an option, when parallel conductors are used. But to be clear, this is what is meant by ?parallel conductors?:
? Take two wires of the same size, run them from one point to another, and connect them together both at the beginning of the run and at the end of the run, and call that set of two wires the ?Phase A? parallel set.
? Take two wires of the same size, run them from one point to another, and connect them together both at the beginning of the run and at the end of the run, and call that set of two wires the ?Phase B? parallel set.
? Take two wires of the same size, run them from one point to another, and connect them together both at the beginning of the run and at the end of the run, and call that set of two wires the ?Phase C? parallel set.
? Take two wires of the same size, run them from one point to another, and connect them together both at the beginning of the run and at the end of the run, and call that set of two wires the ?Neutral? parallel set.

You can run nine wires in the same conduit, if you wish. The nine would be the set of two parallel A?s, the set of two parallel B?s, the set of two parallel C?s, the set of two parallel N?s, and one EGC to serve the entire bunch.

You can also run this in two separate conduits, if you prefer. But that would take a total of 10 wires. One of the two parallel A?s, one of the two parallel B?s, one of the two parallel C?s, one of the two parallel N?s, and one EGC go into one conduit. The other A, B, C, and N go in the other conduit, and the second conduit has to have its own EGC.

 

[Dennis Alwon]

By the way, it's okay to say I'm wrong but to prove I'm wrong with the code is a little more difficult. I am nobodys dummy load.

I don't think proving you wrong is difficult but I do believe convincing that you are incorrect may be a challenge.

 

[charlie b]

You try to rebut me with Articles from the code and I respect that but just because you are one of two moderators responding to my thread doesn't give you the right to misquote or misinterpret the code.

There are three now, and none of us has misinterpreted the code.

By the way, it's okay to say I'm wrong but to prove I'm wrong with the code is a little more difficult. I am nobodys dummy load.

Not all knowledge is contained in the wording of the code. Not all points can be proved or disproved on the basis of code words alone. But I must ask you to keep your language professional and your tone polite. You haven?t crossed any lines yet, but you have stepped close to the edge. We do not permit any kind of personal comments or insulting terms on this forum.

 

[raider1]

You try to rebut me with Articles from the code and I respect that but just because you are one of two moderators responding to my thread doesn't give you the right to misquote or misinterpret the code.

Please show me where I have misquoted or misinterpreted the code.

Also your quote from the code here is about Service conductors from the meter to the main disconnect and it is not about branch conductors from the circuit disconnecting means to interior circuit within the building or occupancy.

My quote was the definition of a separately derived system from Article 100. I was just trying to respond to your statment:

Each complete circuit will be using one of the three possible phases or come from or deliver current to a separately derived system.

I was trying to point out that a circuit does not always come from, or deliever current to a seperately derived system.

By the way, it's okay to say I'm wrong but to prove I'm wrong with the code is a little more difficult. I am nobodys dummy load.

I don't remember ever saying you were a dummy load.

Chris

 

[charlie b]

If you noticed, I also mentioned 310.4 because 300.3 made a reference to it.

True. When it makes that reference, it is telling us that if we choose to use two or more conductors for each phase, we must make the connections in the manner that 310.4 instructs us to use, and we must use the same lengths and materials and sizes and insulation and terminations as 310.4 instructs us to use, and we must do the other three things that 310.4 instructs us to do.

When 300.3(B)(1) speaks of ?to each portion of the paralleled installation,? the term ?portion? means one of the parallel sets. That is, a ?portion? is one A, one B, one C, one N, and one EGC.

 

[randys]

Motors, Air Conditioning, Hvac

Motors, Air Conditioning, Hvac

To Charlie B:

I believe this discussion began with a question about Parallel Installations, can we please stay focused.

Sure, motor and ac/heating circuits use multiple phases but the real question is how are we to deliver the multiple phases required for those circuits. I believe I answered Bill Dozier question in all honesty and reasoning ability. He raised the question and I answered it to the best of my ability. Time to call in the Electrical Inspectors and Moderators who are the AHJ's.

 

[roger]

To Charlie B:

Time to call in the Electrical Inspectors and Moderators who are the AHJ's.

Have you looked at the profiles of those responding?

Roger

 

[raider1]

I believe this discussion began with a question about Parallel Installations, can we please stay focused.

Yes it did begin with a question about parallel conductors in one raceway.

He threw me a curve ball in saying that they had multiple sets of wires in the same conduit. My understanding of this statement is that from poco to the mdp they ran one conduit with two full sets of wires. Is that acceptable. To me it sounds like a major screwup on thier part. What article would address this.

The answer, plain and simple, is that it is OK to run parallel sets of conductors in a single raceway. The conductors must be installed in accordance with 310.4, and because they are run in a single raceway they must comply with the ampacity adjustment provisions of 310.15(B)(2)(a).

Chris