Neutrals and ground on the wrong bus.

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jaggedben said:
That sounds to me like the neutral terminal bar in many service panels.
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And it's not a problem in these cases where the neutral terminal bus is bonded directly to the enclosure, so long as all grounded conductors are kept nearest the grounded service conductor connection and all EGC's are kept farthest. A problem arises where there is no separation that can be called the MBJ, even if only a short section of the bus itself.

Yes, the preceding can be considered being quite nitpicky... but to be lax on the matter creates a violation some will overlook while others may not.
 
K8MHZ said:
The green one.

:p
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Pump panel example I mentioned earlier typically has a 4-7 hole terminal bar for grounded conductors mounted directly to the enclosure. Square D versions I typically use has two mounting screws that are essentially drilled through a terminal position and are tapped into the enclosure wall. Those screws are not green, there is no paint removed behind the bar - it comes already installed and likely is listed as is.

Normal application for me - there is an incoming grounded conductor and an outgoing EGC landed on it and that is it - maybe a second EGC going to a power factor capacitor
 
Smart $ said:
And it's not a problem in these cases where the neutral terminal bus is bonded directly to the enclosure, so long as all grounded conductors are kept nearest the grounded service conductor connection and all EGC's are kept farthest. A problem arises where there is no separation that can be called the MBJ, even if only a short section of the bus itself.

Yes, the preceding can be considered being quite nitpicky... but to be lax on the matter creates a violation some will overlook while others may not.
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Even with the most stringent interpretation of your argument I cannot figure out what code you are citing to support the assertion in red. The terminal bar is unspliced and it is between the service grounded conductor and the EGCs. The location of grounded branch and feeder conductors is not mentioned or entailed by any language that has been cited in this thread. In the case of a tie bar between multiple isolated terminal bars I'll grant the interpretation issues are murkier. But in the case of a single non-isolated bar it seems you are being more than quite nitpicky; you are making up a requirement. It makes no difference to safety or functionality in any case.
 
jaggedben said:
Even with the most stringent interpretation of your argument I cannot figure out what code you are citing to support the assertion in red. The terminal bar is unspliced and it is between the service grounded conductor and the EGCs. The location of grounded branch and feeder conductors is not mentioned or entailed by any language that has been cited in this thread. In the case of a tie bar between multiple isolated terminal bars I'll grant the interpretation issues are murkier. But in the case of a single non-isolated bar it seems you are being more than quite nitpicky; you are making up a requirement. It makes no difference to safety or functionality in any case.
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Let's say you have a three-hole non-isolated neutral terminal bus, holes numbered 1-3, top to bottom. The grounded service conductor is connected to the top hole (#1).

You have one grounded circuit conductor (GCC) and one EGC. Put the EGC in hole #2 and the GCC in hole #3. If the MBJ must be between grounded conductors and EGCs, is there a violation here?
 
Smart $ said:
Let's say you have a three-hole non-isolated neutral terminal bus, holes numbered 1-3, top to bottom. The grounded service conductor is connected to the top hole (#1).

You have one grounded circuit conductor (GCC) and one EGC. Put the EGC in hole #2 and the GCC in hole #3. If the MBJ must be between grounded conductors and EGCs, is there a violation here?
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No. That 's' is not in the code. The code refers to the grounded conductor - singular - in the MBJ definition, and 250.24 clarifies the meaning by referring to the grounded service conductor.
 
wwhitney said:
You have never offered any reason why that would make any difference at all, so I'd be curious to hear your logic on that one.
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I leave some logic to you. I'm perfectly happy with adding a separate EGC terminal bus and calling the factory furnished bolts through their bus the MBJ(s...?). Show me how you can land both grounded circuit conductors and EGCs on the factory furnish terminal bus and still have an MBJ... ;)
 
jaggedben said:
No. That 's' is not in the code. The code refers to the grounded conductor - singular - in the MBJ definition, and 250.24 clarifies the meaning by referring to the grounded service conductor.
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Well in the scenario posed, there is only one grounded circuit conductor, one grounded service conductor, and one equipment grounding conductor... so the plurality I stated in the question is moot. Answer the question.
 
Smart $ said:
Well in the scenario posed, there is only one grounded circuit conductor, one grounded service conductor, and one equipment grounding conductor... so the plurality I stated in the question is moot. Answer the question.
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I answered the question already with a 'no.' The grounded circuit conductor is relevant whether there's one or one hundred.
 
Smart $ said:
I leave some logic to you. I'm perfectly happy with adding a separate EGC terminal bus and calling the factory furnished bolts through their bus the MBJ(s...?). Show me how you can land both grounded circuit conductors and EGCs on the factory furnish terminal bus and still have an MBJ... ;)
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The terminal bar is the MBJ.
 
BTW, I forgot to make the following comment earlier.
jaggedben said:
...it seems you are being more than quite nitpicky; you are making up a requirement. It makes no difference to safety or functionality in any case.
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So do we get to selectively determine Code compliance based on whether an issue makes no difference to safety or functionality?
 
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Smart $ said:
If the terminal bar is the MBJ, exactly how is it between the grounded conductors and the EGC/enclosure?
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Pick a grounded conductor, and pick an EGC. Does the conductive path connecting them pass through the terminal bar? Yes. Then the terminal bar is between the grounded conductor and the EGC.

Cheers, Wayne
 
wwhitney said:
Pick a grounded conductor, and pick an EGC. Does the conductive path connecting them pass through the terminal bar? Yes. Then the terminal bar is between the grounded conductor and the EGC.
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But the GSC is on the opposite side of the EGC. The EGC connection is between the GSC to GCC connection. The GCC is therefore connected to the EGC, not the GSC. :huh:
 
Smart $ said:
Actually, the NEC does require single point system grounding. But the NEC neither uses the terminology or its equivalent nor places any emphasis at all on the concept. It just is what it is.
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I am away from home without my codebook :ashamed: so I cant check the wording, but I thought we could have several GEC's, say for example rods to the meter, and water to the service panel. I know I have done that occasionally, when it has been convenient. (this sounds eerily analogously familiar to the main discussion at hand)
 
Smart $ said:
But the GSC is on the opposite side of the EGC. The EGC connection is between the GSC to GCC connection.
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OK, in the example you and jaggedben are discussing, fine.

Smart $ said:
The GCC is therefore connected to the EGC, not the GSC. :huh:
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You totally lost me, all three are connected together. It's not like the terminal bar only connects a conductor to its closest (two) neighbor(s). I don't see any difference between a terminal bar and a big wirenut, or a linear terminal bar and a hypothetical star shaped terminal bar. They all just connect 2 or more conductors together.

Cheers, Wayne
 
electrofelon said:
I am away from home without my codebook :ashamed: so I cant check the wording, but I thought we could have several GEC's, say for example rods to the meter, and water to the service panel. I know I have done that occasionally, when it has been convenient. (this sounds eerily analogously familiar to the main discussion at hand)
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My reference to single point grounding is regarding the connection of the grounded conductor to the equipment grounding system... not earth grounding.

Earth grounding is for the most part limited to connection of GEC(s) to SEC. Not oft installed, but auxiliary electrodes are permitted.
 
wwhitney said:
OK, in the example you and jaggedben are discussing, fine.


You totally lost me, all three are connected together. It's not like the terminal bar only connects a conductor to its closest (two) neighbor(s). I don't see any difference between a terminal bar and a big wirenut, or a linear terminal bar and a hypothetical star shaped terminal bar. They all just connect 2 or more conductors together.
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That's like comparing a line on a schematic to a real wire. There is no difference between ends of a line on a schematic, but there is for the ends of a real wire. The same is true of a terminal bus when you have to fit an MBJ between conductors and all the conductors are connected to the same terminal bus.

Also not the same as a big wire nut. With wire nut connections, the ends of the wires are touching each other. There is no bus between the wire ends.
 
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