detached garage overhead wire

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texie said:
While we are on the subject of grounded conductor insulation, Am I correct in saying that 250.24(A)(5) is what tells us this? The OP has caused me to realize that this seems a little fuzzy. What am I missing?
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I think that section does the job and it means that the bare conductor in a triplex or quadplex can only be the EGC.
 
don_resqcapt19 said:
I think that section does the job and it means that the bare conductor in a triplex or quadplex can only be the EGC.
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I agree, and that was my point in my first response to the OP. Augie's position was that 200.2 said "if insulated" led him believe that insulation may be optional. I think it is worded that way to cover the rare cases where it is not required, but I don't think it applies in this case. It's an interesting debate, as insulating the grounded conductor does not seem to be very well spelled out even though we intuitively know this for regular feeders and branch circuits.
In any event, IMHO, the inspector is 100% correct in the OP's case.
 
Gregg Harris said:
250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s).

Exception: For installations made in compliance with previous editions of this Code that permitted such connection, the grounded conductor run with the supply to the building or structure shall be permitted to serve as the ground-fault return path if all of the following requirements continue to be met:

  1. An equipment grounding conductor is not run with the supply to the building or structure.
  2. There are no continuous metallic paths bonded to the grounding system in each building or structure involved.
  3. Ground-fault protection of equipment has not been installed on the supply side of the feeder{s).
If the grounded conductor is used for grounding in accordance with the provision of this exception, the size of the grounded conductor shall not be smaller than the larger of either of the following:

  1. That required by 220.61
  2. That required by 250.122
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Would it be safe to say that if he was under a previous edition of the NEC, His installation would be ok with the 3 wire service to the Garage and not need the Equipment grounding conductor?
 
Thank you all for the help. just one last thought- the whole isue started because i didnt run the ground (G) wire overhead, I was just using the ground rod to pick up the ground(G) so to speak- SO lets say if I ran a 12-2 underground and just used a switch for the disconnect means would I still have to install a ground rod?
 
bigdp said:
Thank you all for the help. just one last thought- the whole isue started because i didnt run the ground (G) wire overhead, I was just using the ground rod to pick up the ground(G) so to speak- SO lets say if I ran a 12-2 underground and just used a switch for the disconnect means would I still have to install a ground rod?
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No you wouldn't need to. 250.32(A) exception.

Exception: A grounding electrode shall not be required where only a single branch circuit, including a multiwire branch circuit, supplies the building or structure and the branch circuit includes an equipment grounding conductor for grounding the normally non?current-carrying metal parts of equipment.
 
bigdp said:
Me ... Here is what i did- I ran #4(AL) triplex wire from the house to the garage (2H, 1N) at the disconnect on the garage I have a ground wire #6 that attaches to the ground rod. This is ... Thanks[/QUOTE

My question is, " did you separate the ground/EGC from the neutral and "float" the neutral at the Garage disconnect "?
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I also think the inspector is correct.

Since the inspector required the fourth conductor or a separate grounding conductor
he is making it a sub Panel.

How would this sub panel operate correctly as a sub panel under a fault if the neutral
was not insulated?
 
There is one more solution to this feeder if you don't want to replace the triplex. That is to make it a 120V only feeder. Use the two insulated wires as hot and neutral, and the bare messenger as the ground. You'll still need the panel and ground electrode system if the feeder is breakered at over 20A. Don't know if you can live with 120V only and half the originally planned power.
 
ronaldrc said:
I also think the inspector is correct.

Since the inspector required the fourth conductor or a separate grounding conductor
he is making it a sub Panel.

How would this sub panel operate correctly as a sub panel under a fault if the neutral
was not insulated?
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The inspector's not making this a subpanel, that's what it is regardless.

The neutral being insulated or not would not have any bearing on its fault clearing capabilities.

Thousands of old installs exist where they used to use triplex, 2 insulated with the uninsulated used as the neutral,without the 4th wire or ground.

They used to rebond the neutral to the disconnect or subpanel at the outbuilding.

We've progressed since then.

There were exceptions where you could still use this type of Triplex installation in previous code issues,
But not anymore.

The inspector is correct since this is the new way of doing things per current code.
 
Where did you see in my post anything about fault clearing.
It is more of a shock hazard without the insulated neutral and a bare
grounding conductor. :)
 
ronaldrc said:
Where did you see in my post anything about fault clearing.
It is more of a shock hazard without the insulated neutral and a bare
grounding conductor. :)
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How would this sub panel operate correctly as a sub panel under a fault if the neutral
was not insulated?
 
Jap

It would be more of a shock hazard.
What would be the reason of not using the insulated wire as the neutral if you have that choice?
 
ronaldrc said:
Jap

It would be more of a shock hazard.
What would be the reason of not using the insulated wire as the neutral if you have that choice?
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When you asked the question of "How would this subpanel operate correctly as a subpanel "Under a Fault" if the Neutral was not Insulated,,,,,,,,,,,,,,,,,,,


What did you mean by that?
 
Okay Jap

Forget about the insulated conductor he or you would use as the grounding conductor for right now.

lets just look at the circuit as the old three wire feeder using the uninsulated ground conductor as the neutral.

let say you are feeding a air compressor in this garage and the neutral is bonded to the compressor
tank. Which if wired the old way would be.


Now the pressure switch on the compressor closes to start the compressor. The voltage runs through
the motor windings back to the neutral to return to the main panel feed neutral in the house.

If for some reason the neutral feeding your sub panel in the main in the house came loose, what electrical potential would the tank be in respects to the ground?
 
I understand all of that,that's just simple electicity, that's not what I'm questioning.

What I didnt understand is when you asked, Quote"How would this panel operate as a subpanel under a Fault if the Neutral was uninsulated".

There are several Old installations that have a triplex 2 insulated and 1 uninsuated overhead aerial servic feeding a subpanel at a seperate structure.

The answer to the question above is the Panel would operate the same wether the Neutral was insulated or not.

In the Old installations with the 3 wire Feeders there was either no ground wire at all pulled to the outlets or if a ground wire was pulled to the outlets or pieces of equipment you had to bond the equipment grounding conductors to the Neutral at the Subpanel so in the case of a fault, the fault would have a path back to the service neutral to be able to facilitate the operation of the overcurrent device.

Did you mean to ask "What would happen if the Neutral from the House to the Subpanel was to become disconnected?
If so the answer then would be Yes, all of the non current carrying would become energized on a 3 wire feeder where the Neutral and Ground was not seperated.

The question just didnt make sense to me.

Much like the 3 way switch diagram you have shown next to your name on your posts.
The source of the 120v circuit is indicated by the two arrows pointing to the left, but yet it shows the neutral conductor grounded at a point beyond the source. This schematic is drawn as a code violation. The Neutral should be drawn grounded at the source not beyond that. That wiring diagram is a schematic for a parallel return path which is a code violation and a shock hazard.
 
ronaldrc said:
Jap

I apologize maybe the way I said that was misleading.
Like you said if you don't insulate the neutral you would
have paralleled grounds and that would not be a correct
circuit.

Please click on the link below to see how I think the 2 and 3 wire
systems work.

http://home.comcast.net/~ronaldrc/wsb/grounding.htm
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I never said anything about insulating the neutral.
I'm saying all of the old 3 wire overhead services to a seperate structure were fed with triplex in which the bare "Uninsulated" conductor with the messenger in it was always used as the neutral and the 4th equipment grounding conductor was not required.

Unlike today where the Neutral and the grounds must be kept completely seperate beyond the service point.

If your meaning that now a grounded conductor (Neutral) and and equipment Grounding conductor are required to be bonded together at the Service Point but are required to be "Isolated" from each other from that point on, your talking my language.
 
jap said:
I never said anything about insulating the neutral.
I'm saying all of the old 3 wire overhead services to a seperate structure were fed with triplex in which the bare "Uninsulated" conductor with the messenger in it was always used as the neutral and the 4th equipment grounding conductor was not required.

Unlike today where the Neutral and the grounds must be kept completely seperate beyond the service point.

If your meaning that now a grounded conductor (Neutral) and and equipment Grounding conductor are required to be bonded together at the Service Point but are required to be "Isolated" from each other from that point on, your talking my language.
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Yes that is what I am saying. :)
 
jap said:
Much like the 3 way switch diagram you have shown next to your name on your posts.
The source of the 120v circuit is indicated by the two arrows pointing to the left, but yet it shows the neutral conductor grounded at a point beyond the source. This schematic is drawn as a code violation. The Neutral should be drawn grounded at the source not beyond that. That wiring diagram is a schematic for a parallel return path which is a code violation and a shock hazard.
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That's always been my biggest problems boy you better believe it,I I make as many mistakes as anybody.
And I don't always read the response as thoroughly as I should.

Some people will go to any extreme to make you look wrong. Your quote above just proves that
but please don't feel like the lone Ranger you have plenty of company.

In my light that is the green grounding screw in the fixture.


Thanks for being so courteous.

Ronald :)
 
When you replied "Okay Jap", the typing sounded like you were gearing up for a battle to explain a simple electrical

event that occurs when a neutral becomes disconnected, and the Neutral and Ground are bonded together in a subpanel,

which was somewhat belittling to someone who's been in the electrical field for 30 years.

I guess I need to quit posting replies.

I cant seem to type what i'm trying to say without it coming across the wrong way.

Sorry if I offended you that was never my intention.
 
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