Contradiction

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Volta said:
Isn't the first graphic showing a grounded conductor detached at the load end and its terminal incorrectly rebonded to the enclosure? That leaves the loose raceway connections to carry the full neutral current until repaired.
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Even if it were connected, it would still be carrying 50% of the current - and I doubt it would pass on the 5mA range for personell protection afforded to GFCI's for the same reasons on branch circuits.

Volta said:
The second is just showing how proper bonding will ensure a good path when needed for fault current, though I don't know why the text says "only one end".
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That is something else I'll attack after a cooling out period.... A different thread....
 
jim dungar said:
In the first picture, the service neutral conductor is not connected to the neutral bus but the grounding conductor is, this causes current to flow along the conduit which is described as being a loose connection. Continuous current through a bad connection results in heat.
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And 50% of that current does not?
1113844669_2.jpg
 
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jim dungar said:
In the first picture, the service neutral conductor is not connected to the neutral bus but the grounding conductor is, this causes current to flow along the conduit which is described as being a loose connection. Continuous current through a bad connection results in heat.
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What ensures that the unbonded side of the raceway between the meter and main is not loosely joined? Or hand tight on paint?


1113921646_10.jpg
 
I may not be getting it, but the full graphic from post #22 is showing improperly rebonded grounded wires in both scenarios, so objectionable current flows on the conduit, maybe the 50% you mention, if the 2nd bonding jumper is removed, none.

In the first image, 100% of the obj. current flows, if the 2nd bonding jumper is removed, none, just the regular lost neutral troubles.
 
Volta said:
I may not be getting it,
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You see I'm trying to point out the contradiction of not allowing secondary neutral bonds after the main - Which are DANGEROUS!!!! And Not allowed by code.

But somehow - the same type of condition of grounded conductor to equipment grounding connections is OK - even required in some cases prior to the main.
 
The 50% statement is a hang over of 110.27.

How you want to run with that could, well it could be appliable or required.

I don't see what the problem is, the service lateral is just different it's not in our rules.

Try NEC Code, 110.8 first sentence.,
Or even 110.10 (in the sense of what your trying to protect),
110.12 just doesn't say exactly what I want it to say, but it is still a
Mech. Execution of Work. Put a old screw driver to the lock nut, gezz...

Underling all this, please recall its an Electro Motor Force thats in play,
Last I heard the neutral can still carry the unbalanced load.
The diagrams are to understand the application of error... Maybe the spot the error is on the user!
 
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e57 said:
You see I'm trying to point out the contradiction of not allowing secondary neutral bonds after the main - Which are DANGEROUS!!!! And Not allowed by code.

But somehow - the same type of condition of grounded conductor to equipment grounding connections is OK - even required in some cases prior to the main.
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This is nothing new your pointing out, it has been discussed many times here and I am sure many places. Your right it is a contradiction, one that has existed since the start of the rules as far as I can tell.
 
e57 said:
50 volts is safe? What/where is that based on?
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OSHA

OSHA does not require PPE for under 50 volts.

But seeing as we are talking no more then a few feet of neutral conductor the real world voltage drop would be more likely less then a couple of volts.

Even if there was very little voltage difference - touching the gutter and one of the main panels puts your body in parallel with the current of the neutral if using PVC nipples.
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In parallel, in series, the current is irrelevant if the voltage is low.

Using steel/metalic puts you in parallel with the hopefully well joined/bonded enclosures and raceways - which should in therory be the same potential. (even if they are carrying current)
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The steel nipples will have voltage drop across them just like the conductor inside them would.
 
e57 said:
You see I'm trying to point out the contradiction of not allowing secondary neutral bonds after the main - Which are DANGEROUS!!!! And Not allowed by code.

But somehow - the same type of condition of grounded conductor to equipment grounding connections is OK - even required in some cases prior to the main.
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I'm going to plead ignorance here. Where is this allowed under code?

Edit: I don't mean at the service.
 
I didn't mean to post three times in a row but I ran out of time to edit.

I admittadly haven't read most of the thread but I know Bob knows why we can only ground the neutral once after the service entrance. I really just don't see nearly, I mean nearly, as much chance of heating grounded conduits on the power company side.
 
physis said:
I didn't mean to post three times in a row but I ran out of time to edit.

I admittadly haven't read most of the thread but I know Bob knows why we can only ground the neutral once after the service entrance. I really just don't see nearly, I mean nearly, as much chance of heating grounded conduits on the power company side.
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I do...I have seen a lot more open neutrals on the line side of the service than on the load side.
 
don_resqcapt19 said:
I do...I have seen a lot more open neutrals on the line side of the service than on the load side.
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Which - in one way, makes having a current carrying nipple between the meter and main - 'safer' - if the neutral fails between them the building has a better chance of not going Hi/Low. (So long as there is a relatively good connection on both sides.)
 
iwire said:
Its one of those things I just accept and move on, I have started intentionally using PVC nipples to avoid the issue.:smile:
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After reading this whole thread it makes a whole lot of sense why I see so many services done completely in PVC here. I've noticed them but I never really thought about it this much.
 
daleuger said:
After reading this whole thread it makes a whole lot of sense why I see so many services done completely in PVC here. I've noticed them but I never really thought about it this much.
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Where you are at - I'm sure it has more to do with rust and sea air. (Just stuck my sister in-law on a plane back there to Halifax)
 
e57 said:
Where you are at - I'm sure it has more to do with rust and sea air. (Just stuck my sister in-law on a plane back there to Halifax)
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That could be, but the whole neutral bonding making a big neutral out of all the enclosures and fittings would make sense too.

I'm about an hour from Halifax, but I'm all lined up with another contractor and going to Labrador at the end of March. :D
 
daleuger said:
After reading this whole thread it makes a whole lot of sense why I see so many services done completely in PVC here. I've noticed them but I never really thought about it this much.
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This also makes my eye-brow twitch - why is there no market of PVC service enclosures? There are obviously places where PVC is allowed for service conductors (unlike here), but not a deluge of PVC meter and main pans - like they have in Europe. (where from what I understand you can get nothing but non-metallic enclosures?)
 
There's a pretty good mix on the meter cans and etc, but risers, weatherheads, nipples....PVC. I've done enough of them in all metal to feel your pain.
 
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