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Sub Panel Neutral & Grounds


NJinspector
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Can someone please "Katenize me"

In the basement subpanel the neutral and ground wires are sharing the same connection points. This is a dangerous condition since in a subpanel the neutral wires are carrying current. Normally, ground wires are only carrying current if something goes wrong, but because the neutrals and grounds are not isolated, all ground wires are now carrying current as well. Have a reputable electrician separate the neutrals and grounds to prevent any potential hazards.

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Can someone please "Katenize me"

In the basement subpanel the neutral and ground wires are sharing the same connection points. This is a dangerous condition since in a subpanel the neutral wires are carrying current. Normally, ground wires are only carrying current if something goes wrong, but because the neutrals and grounds are not isolated, all ground wires are now carrying current as well. Have a reputable electrician separate the neutrals and grounds to prevent any potential hazards.

Sorry. Only Jim K is vested with the authority to Katenize.

Marc

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Sorry, I don't have the authority to "Katenize" you.

I begin my reporting with something like this when there is a 3-wire feeder. Or, you can change to 4-wire feeder depending on what's there:

Electrical Safety Concern/Immediate Attention Recommended: The feeder to Sub-panel has three conductor wires instead of the required four. When 120 V circuits are in place, the wiring to sub-panels must contain two hot wires, one neutral and one ground in order to prevent the possibility of current returning on equipment grounding conductors "EGC", enclosures or piping. Neutral wires are required to be isolated from the panel. In this case, the wiring configuration violates industry standard requirements. Recommend repair by a qualified licensed electrician.

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Can someone please "Katenize me"

In the basement subpanel the neutral and ground wires are sharing the same connection points. This is a dangerous condition since in a subpanel the neutral wires are carrying current. Normally, ground wires are only carrying current if something goes wrong, but because the neutrals and grounds are not isolated, all ground wires are now carrying current as well. Have a reputable electrician separate the neutrals and grounds to prevent any potential hazards.

That's a tough one because you have to decide to what degree you wish to explain the mechanics behind the issue. If you favor the lean approach, Neal's example is fine -- though I'd add a what-bad-thing-can-happen sentence so the readers will know why they should care.

If you want to communicate a sense of *why* the ground-neutral sharing thing is a problem, your explanation is ok, but could use a little tightening up.

In the basement subpanel the neutral and ground wires are sharing share the same connection points. This is a dangerous condition. since in a subpanel the neutral wires are carrying current. Normally, ground wires are only carrying only carry current if something goes wrong, but because the neutrals and grounds are not isolated, all ground wires are now carrying current as well on this panel, they're energized all the time. Have a reputable electrician separate the neutrals and grounds to prevent any potential eliminate any hazards.

Note that I made one correction in your explanation that was technically incorrect. When the neutrals aren't properly isolated, the grounding wires don't necessarily "carry current" as a result. They have voltage potential though. That's why I used the word energized.

I've observed something peculiar about my own report writing. With most issues, I tend to write fairly short direct notes, like what Neal wrote. But when it comes to electrical issues, I tend to overdo. For instance, if a joist were too small, I'd just say, "Such & such a joist is too small. It might break. Have it repaired or replaced." Or something similar. I wouldn't write, "Such & such a joist is too small. Joists need to be sized to match the design load of the floor assembly. If a joist is too small, it could fail in deflection, bending, vertical shear, or horizontal shear as the fibers in the wood fail to adequately resist the stresses that are imposed on it by the mass of people and objects and the force of gravity that acts upon them." Yet, some of my electrical notes are nearly that ridiculous.

I have to keep telling myself to simplify.

- Jim Katen, Oregon

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....

If you want to communicate a sense of *why* the ground-neutral sharing thing is a problem, your explanation is ok, but could use a little tightening up.

In the basement subpanel the neutral and ground wires are sharing share the same connection points. This is a dangerous condition. since in a subpanel the neutral wires are carrying current. Normally, ground wires are only carrying only carry current if something goes wrong, but because the neutrals and grounds are not isolated, all ground wires are now carrying current as well on this panel, they're energized all the time. Have a reputable electrician separate the neutrals and grounds to prevent any potential eliminate any hazards.

Note that I made one correction in your explanation that was technically incorrect. When the neutrals aren't properly isolated, the grounding wires don't necessarily "carry current" as a result. They have voltage potential though. That's why I used the word energized.

....

Hi Jim. If we are talking about the circuit grounding conductors, from the panel to the outlets, I'm having a hard time with why those would be any more energized, or have more potential, in the OP's set-up over those emanating from a service panel where the grounds and neutrals are correctly bonded. I thought (think) the main difference and safety issue was the way neutral current is passed back to the service panel. With an improperly bonded sub, some of that current will be present along any grounding path between both panels. The whole parallel path thingy, no?

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. . . Hi Jim. If we are talking about the circuit grounding conductors, from the panel to the outlets, I'm having a hard time with why those would be any more energized, or have more potential, in the OP's set-up over those emanating from a service panel where the grounds and neutrals are correctly bonded. I thought (think) the main difference and safety issue was the way neutral current is passed back to the service panel. With an improperly bonded sub, some of that current will be present along any grounding path between both panels. The whole parallel path thingy, no?

That's true, but both things are happening. It depends on which grounding wires you're talking about. Those wires that do, indeed, take part in a parallel path back to the service panel will carry a portion of the current that's being used by devices fed from the sub panel. That'll cause imbalances and the headaches associated with them. But that isn't true for most of the grounding wires associated with that panel. Most of them just sit there with a small voltage potential, waiting for someone to complete the path. Even then, unless the path has particularly low impedance, the person completing the path is unlikely to suffer from the experience.

I think that trying to explain all that in an inspection report would have few rewards. Another argument for Neal's version.

- Jim Katen, Oregon

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That's a tough one because you have to decide to what degree you wish to explain the mechanics behind the issue. If you favor the lean approach, Neal's example is fine -- though I'd add a what-bad-thing-can-happen sentence so the readers will know why they should care.

That was my thought as well. I'd add "This can cause electricity to flow through other parts of the building where it was not intended (such as plumbing pipes, gas pipes, communications wires, etc.)." That puts it into a realm the average Joe can relate to.

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That's a tough one because you have to decide to what degree you wish to explain the mechanics behind the issue. If you favor the lean approach, Neal's example is fine -- though I'd add a what-bad-thing-can-happen sentence so the readers will know why they should care.

That was my thought as well. I'd add "This can cause electricity to flow through other parts of the building where it was not intended (such as plumbing pipes, gas pipes, communications wires, etc.)." That puts it into a realm the average Joe can relate to.

I just say it poses a shock hazard; no written explanation why. If ever one day somebody asks why, I'll explain further. Haven't had to yet save a few short spoken words on-site every once in a blue moon.

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