Parallel feeders single phase

[iwire]

Re: Parallel feeders single phase

Originally posted by milwaukeesteve:
This style of wiring that you are arguing is not general wiring, as you mentioned. It has specifics steps to take within the code rule itself, that is not 'general'.

That is your opinion, and that is fine. To some of us it as 'general' as wiring 20 amp branch circuits.

Originally posted by milwaukeesteve:
Iwire,
You neglected to read all the reply. It is not just the locknut. It is any ferrous material that forms a circle around the conductor. That includes the cabinet,

I am fully aware of that, take a look at the picture I posted of the single conductor MI cable installation into a steel cabinet.

The feris metal is cut out and non-ferris metal is put in it's place.

Originally posted by milwaukeesteve:
and like I mentioned, what if the dog's chain got tied around the pipe. As soon as it forms a circle, you have an electromagnet.

What if?

What if someone drives a screw into a meter socket?

My point here is any installation can be what if'ed into a dangerous situation.

Originally posted by milwaukeesteve:
Why would you guys even be arguing this? Like Shelco said, do it the proper way. Leave this type of installation for where you absolutely need it. (this is not one of those times)

Again it is all just opinion, it is code compliant without 'twisting' or pulling apart the code. It is a design decision plain and simple. Any code compliant way can be the 'proper way'.

To each their own, my stake in this thread is only that some folks are insinuating the code must be twisted or ignored to provide isolated phase installations and that is simply not true.

No more than running multi-wire branch circuits is twisting the code.

 

[iwire]

Re: Parallel feeders single phase

Originally posted by inspector 102:
Others in the office are just looking at me and shaking their heads.

That happens with me here at home, my wife just looks at me and rolls her eyes.

 

[roger]

Re: Parallel feeders single phase

Steve to add to Iwires post, if it scares you stay away from it. It seems as though you want your tunnel vision to be shared by every one else.

Shelco, (Steve you can listen too) one very good reason to use this method is space, neatness, and keeping conductors the same length in tri, quad or more installations.

Imagine a service or feeder with 4 raceways containing 4 600 KCMIL's in each raceway coming into an enclosure above the termination point where there is only 3' of space.

If you have ever wrestled 600 KCMIL you will know that the less bending the better.

By laying out each raceway containing all A phase in one, B phase in one, C phase in one, and Neutrals in one, left to right above the terminations, you will have a much easier and efficient (even helps your AC concerns Steve) installation.

Steve, is it your desire to have others only learn parts of the code you deem usable?

Roger

[ May 26, 2005, 05:58 PM: Message edited by: roger ]

 

[shelco]

Re: Parallel feeders single phase

I have done this type of installation a number of times, (4 runs of 600 mcm).

Ok roger you win.
All of us are wrong.
If doing it in a way that avoids controversy with the AHJ an not having to fight the fight just to prove that I know the code is tunnel visioned then so be it I am tunnel visioned.

[ May 26, 2005, 07:23 PM: Message edited by: shelco ]

 

[roger]

Re: Parallel feeders single phase

Shelco, it's not a matter of winning or loosing, it's the fact that it is code compliant.

If doing it in a way that avoids controversy with the AHJ an not having to fight the fight

I have never had to fight an inspector over this type of installation, they are aware of it being code compliant.

What is the name of this page that host these forums anyways?

Would you rather it be Selected Parts Of The National Electrical Code INTERNET CONNECTION?


Roger

 

[shelco]

Re: Parallel feeders single phase

Yeah but...Oh never mind.

It is code compliant If all conditions are met.
Would you not agree however that the orininal post situation is not code compliant?

 

[milwaukeesteve]

Re: Parallel feeders single phase

I will second Shelco.
Does this original installation that is mentioned by Wayne have anything to do with what you are arguing? No.


I agree that if you WERE to put all the same conductors in one raceway, it would make it easier to match them, but only how much. You still have to lay out your conductors first, then install them. Otherwise you can't make sure you got the same length.


My (and Shelco's) so called tunnel vision is based on safety and proper installation. Just because the code says you can do something, does mean you should. Can and Shall are different.
Besides, I can't have tunnel vision if I do see your type of installation working. My argument is that this is not something that should be taken lightly, and is not something that pertains to Waynes original question.


In regards to the stage example, these conductors are designed for use this way, and are designed for temporary installations, lasting a show at a time.
We are talking about permanent installations with permanent consequences if not installed properly. The 'choking effect' is very dangerous. The smaller the ampacity, the longer it takes. The larger the ampacity, the shorter it takes, and can be quite damaging when it happens.

 

[roger]

Re: Parallel feeders single phase

Steve and Shelco, go back and read all of Waynes posts and then explain (quote please) where he has given enough information to determine that the installation he speaks of is not installed this way.

Roger

 

[milwaukeesteve]

Re: Parallel feeders single phase

Posted by Roger

Now this being the case, If these parallel runs are in fact in PVC, I can't see where there would be any problem with the instalation described by Wayne other than the fact it is not an everyday run of the mill installation.

and again by roger

If they are in PVC there is no problem, like I said, I have done it. Have you read 300.3(B)?

again by roger

Wayne said PVC, read 300.3(B)(3) as Charlie pointed out.

again

Read 300.3(B)(3) again.

BTW, I,m pointing out methods and code, you seem to be arguing.

First of all, Roger, I am not picking on you only, Bob is next.

300.3(B)(1) does not mention anything about PVC raceways installed above ground
300.3(B)(3) does not mention anything about PVC raceway installations. If you read the code rule, it mentions wiring methods with non metallic sheath, where run in different raceways.... Nothing about PVC raceways.

Bob,

How about a die-cast lock ring?

Non-ferris is not the same as non-metallic.

The fact is isolated phase installations are safe and can be code complaint.

Most MI cable installations are isolated phase.

First, where does the code rule say anything about a non ferrous lock ring?
Second, true, nonferrous and non metallic are not the same, but still it does you nothing since same phase conductors cannot be ran in PVC above ground.
Third, isolated phase installations can be code compliant. That is if you do follow the code. The code does spell out specifically when you can do that.
Fourth, yes, but that does not help wayne's example, and again, that is a specific installation.

I don't see why you guys are trying to argue so hard on this PVC installation method, and roger, stop pointing out 300.3(B)(3) to help your argument when it helps mine instead.

 

[charlie]

Re: Parallel feeders single phase

(3) Nonferrous Wiring Methods Conductors in wiring methods with a nonmetallic or other nonmagnetic sheath, where run in different raceways, auxiliary gutters, cable trays, trenches, cables, or cords, shall comply with the provisions of 300.20(B). Conductors in single-conductor Type MI cable with a nonmagnetic sheath shall comply with the provisions of 332.31. Conductors of single-conductor Type MC cable with a nonmagnetic sheath shall comply with the provisions of 330.31, 330.116, and 300.20(B).

"Conductors in wiring methods with a nonmetallic . . ." would indicate to me any single conductors that would be installed in a raceway. I grant you that PVC is not mentioned but it is not excluded.

 

[milwaukeesteve]

Re: Parallel feeders single phase

This would mean that you would have to install the conductors in a 'wiring method' with a nonmetallic sheath, say PVC, 'where run in' a raceway, say what? more PVC.
So theoretically you could run these parallel conductors in PVC inside more PVC. Interesting.
You skipped the first part of the statement, and went right to the words non metallic and raceway. Interesting.


This code rule again does not say that parallel conductors can be ran in PVC. And the other rule only allows it underground.

[ May 27, 2005, 01:09 PM: Message edited by: milwaukeesteve ]

 

[roger]

Re: Parallel feeders single phase

Steve, don't worry about picking on me, until you make your point it means nothing.

You need to read the other posts closer, I didn't ask you to go back and read my posts, I asked you to go back and read Wayne's posts.

Like I said before, if it scares you don't do it.

300.3(B)(3) does not mention anything about PVC raceway installations. If you read the code rule, it mentions wiring methods with non metallic sheath, where run in different raceways.... Nothing about PVC raceways.

What type of raceways would you run these cables in? Where do you see PVC prohibited?

Now, if you would, go back and read Wayne's posts, then tell me where he said these were not some type of NM sheathed cable.

I know that this situation Wayne is describing is most likely not in compliance, but as I have said, we don't have enough information do we?

BTW, if it would make you feel better to get your "Inductive Heating" knowledge out on the table, why not start a thread covering it and how to avoid it.

If the NEC (even sections you may not routinely use) is followed these issues as well as other EMF problems and suspected dangers will be nullified.

Roger

 

[roger]

Re: Parallel feeders single phase

Steve,

So theoretically you could run these parallel conductors in PVC inside more PVC. Interesting.

yep that's what it means, you can run conductors in an inner duct, PVC sheathed NM, SE, USE, UF, plain old THHN/THWN, (has a jacket or a sheath if you will) etc... inside a PVC raceway.

Roger

[ May 27, 2005, 01:36 PM: Message edited by: roger ]

 

[milwaukeesteve]

Re: Parallel feeders single phase

That installation is fine (that you just mentioned). But this is not what we are talking about.

Wayne's example is running 2 runs of PVC counduit to the main panel, and running the phase conductors together, not the circuit conductors.

300.3(b)(3) does not talk about this.

To make this installation legal, according to 300.3(B)(3), you would have to somehow run (2) 2 1/2" PVC conduits inside a 6" PVC conduit. Then somehow connect these to both cabinets (following 300.20). The 6" PVC could come into the cabinet like normal, and the 2 1/2" conduits would stub into the cabinet through the 6"knockout.


Roger and Bob wanted to skip a few words in 300.3(B)(3). Charlie, you at least got all the words right, but need to apply it correctly.
The conductors must be in a wiring method that is run in a raceway, and all the wiring methods must be grouped together inside the raceway.

MI inside PVC -fine
MI inside EMT - fine
pvc inside trough - fine
liquid tite non metallic inside a rigid nipple -fine
All the above are fine as long as all of the circuit wiring methods are contained inside the same raceway.
That is code rule.
IF installed this way there would be no EM effects (choking) at cabinets or enclosures.
That is deductive reasoning.

 

[milwaukeesteve]

Re: Parallel feeders single phase

I cannot continue anymore for now.
I am off the the northwoods of Wisconsin this afternoon.
I won't have Internet until Tuesday.

That will give you the weekend guys to brush up on your arguments on this.
I'm sure Shelco can handle it too.

Have a great Memorial Day weekend!

 

[roger]

Re: Parallel feeders single phase

Steve, it will be best if you just stay away from this type of installation, you do not have a firm understanding of how it works.

When in doubt, Let those who know or have used a particular method reply to these types of topics.

Enjoy your weekend.

Roger

 

[shelco]

Re: Parallel feeders single phase

whew
ok here we go.
Wayne said the conductors were run in "conduit" from a "Meterbase" to a 400 amp "panel". this is an athletic complex so it stands to reason that the neter base is "steel", the panel is "steel" and even if the conduit was PVC the locknuts would be "steel". thus not code compliant.
Now I know that these are assumptions but lets be real we all know that this is the way it is.
The other installation method has nothing to do with being afraid of doing it this way it simply
makes no sense at least to me to do it this way unless it must be done this way for some reason or another. What would be the point, and again this is my opinion and method, my choice.
Some people just like to be different just for the sake of being different. Not a thing wrong with that It is just not my style.
Done
I am hopping on the Harley and hitting road for the week end.
Need to rejuvinate.

 

[milwaukeesteve]

Re: Parallel feeders single phase

OK Roger,
I am back for a brief bit. I have a Mother in law that just passed away, so I don't have time for chit-chat.

I take offense to your last reply to me. That was not appropriate, and it was uncalled for.
I know basic electric theory, and I know what the code rules state for parallel conductors.

The type of installations that you keep talking about are not what Wayne is looking for.
You are talking about something very different. The picture you posted shows the proper way of doing it if you needed to install it that way, NON FERROUS connectors and NON FERROUS plate cut in. That is A correct installation.

However, when you talk about running the same phase conductor inside raceways, this can be very dangerous. The code rule and common sense tell you how to run these. This is not just an everyday installation. Your mentioning of how to run these in conduit do not address the severity of danger that can arise by not installing it correctly.
You talk lightly about this, but this is serious.
There is great danger in 'choking' a conductor. ESPECIALLY service conductors of high amperage.

The code rule is specific in saying all circuit conductors need to be ran together, NOT phase conductors.
The code rule is specific is saying when non METALLIC raceways can be used; underground.
The code rule is very specific in Non FERROUS Wiring Methods; non metallic sheath ran in a raceway, OR MI cable w/ non magnetic sheath, OR MC cable with non magnetic sheath.

What the code rules state are very specific installation methods when running phase conductors. Your comment about how this is 'general' wiring is irresponsible. It is in the general wiring area, but the rules are VERY specific, and not 'general'.

Whether Wayne is a novice, apprentice, journeyman or Master, he came here looking for advice. YOU are the one that is talking about something off course. I have been repeatedly, along with Shelco, trying to steer this thread/argument back to Waynes post. As Shelco just mentioned, we know what type of installation this is. The guy did not follow the code rules. We also know that what you are talking about is related, BUT NOT RELEVANT. YET, if you were to succeed in telling Wayne that there is nothing wrong with his installation problem because of all of your tangent arguments, then that would be irresponsible on your part. The results of an installation such as this could be very damaging, yet you are continuing to argue things that could confuse someone looking for answers and confirmation.

I base my comments on the following:
-The Code Rules as written (no interpretation, no handbook) and have stated the code rules throughout.
-Basic Electric Theory and Electromagnetic Properties; these both tell me about the relationship between a phase conductor and a metal circle or a coil of phase conductor around a metal core. (metal meaning magnetic metal)
-Common sense tells me that a metal locknut or metal cabinet around a phase conductor creates an electromagnet (just like a Current Transformer)
-Practical Safeguarding (90.1(a)); all installations should be focused towards electrical safety first, not practicality, cost, ease, time or anything else

If anyone should stay away from this topic it should be you. Save your arguments for when it is on topic.

 

[roger]

Re: Parallel feeders single phase

Steve, my condolences to you and your family.

Roger

 

[don_resqcapt19]

Re: Parallel feeders single phase

Steve,
Rogger's posts on what the code permits are correct, in my opinion.
Don