I am installing a 400A Service using 320 Metercan and coming off the load side of meter can with 2-2" conduits to two 200A disconnects. My question is can I install a J-box and run Bldg steel, water pipe GEC's to a ground bar in j-box and then run #4 to each disconnect to bond the service disconnects. My GEC to ground rod will take place at the meter can per PoCo. All my conductors will be ran exposed( Unless code prohibits). If anyone has a photo of this type of installation and could post it that would be very helpful. The disconnects dont have the required space to make these connections. I do not know how to add pictures on this site.
Installing GEC conductors without a Gutter
- Thread starter wmeek
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jumper
Senior Member
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- 3 Hr 2 Min from Winged Horses
See post #45 for instructions.
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- Chapel Hill, NC
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- Retired Electrical Contractor
Post #45????
- Location
- Chapel Hill, NC
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- Retired Electrical Contractor
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I do this install all the time but why not just run the GEC to meter base. There is usually room for the #6 ground rod electrode and the gec to the building water pipes. You can then jump from the water pipe to the building steel.
jumper
Senior Member
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- 3 Hr 2 Min from Winged Horses
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- Chapel Hill, NC
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- Retired Electrical Contractor
Yes... but you do not have to install a J-box w/grd bar to do it. The #4 GEC tap to #2 GEC(s) connection can be made exposed. See 250.64(D)(1) for details.
So if I run The #1/0 GEC from the building steel to the Neutral in the Meter can and a run#6 GEC from meter can to ground rod and jumper a #1/0 From building steel to water pipe and run a bonding jumper from neutral in disconnects to a grounding bushing on supply side conduits and bond the neutral at both disconnects would meet the NEC .
- Location
- Chapel Hill, NC
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- Retired Electrical Contractor
Good point I meant to add that but got distracted with a phone call and teasing Derek.
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- Chapel Hill, NC
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- Retired Electrical Contractor
petersonra
Senior Member
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- Northern illinois
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- engineer
where does it say that?
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- Chapel Hill, NC
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- Retired Electrical Contractor
Well, I am not sure. I have always understood that the water line was the primary electrode. I have not been able to confirm this so..... I guess I got it from the fact that only a water pipe has to be supplemented by another electrode so they were all the supplemental electrode-- 250.54(D)(2). IMO this means the water pipe first....
250.64 (F)(1) allows the GEC to be connected to any convenient grounding electrode within the grounding electrode system. If that happens to be the building steel, no problem as long as the water pipe is bonded to the building steel.
david
Senior Member
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- Pennsylvania
It depends on if the building steel is a grounding electrode or not. What you are bonding is a grounding electrode system. If the building steel is a grounding electrode, then you can bond the building steel electrode to the water pipe electrode.
If the building steel is not a grounding electrode then you are only added a grounding electrode to the building steel by bonding the water pipe to the building steel.
david
Senior Member
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- Pennsylvania
The water pipe is a grounding electrode and needs to be bonded to the system nutral ( service)or bonded to another grounding electrode to be part of the grounding electrode sytem
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- Massachusetts
No such thing as 'the primary electrode' although I see many people use the term.
The fact that it must be supplemented does not make it the 'primary electrode' it actually means it is less reliable.
- Location
- Chapel Hill, NC
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- Retired Electrical Contractor
Yeah I sort of said there is no primary but I still think of it as main or primary electrode.
So if the water pipe is an electrode and the building steel is not - as is often the case- are you saying I can bond the steel and then use a bonding jumper to the water pipes? I don't think so unless the connection is irreversible.
So if the water pipe is an electrode and the building steel is not - as is often the case- are you saying I can bond the steel and then use a bonding jumper to the water pipes? I don't think so unless the connection is irreversible.
I would love to do a 3 point test to a copper pipe and see what one would get. I suspect it gets supplemented because the pipe over time may get replaced with plastic in entirety or in sections--
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In that case, the building steel is not part of the grounding electrode system. The GEC needs to go to an electrode, probably the water pipe, but the water pipe will need to be supplemented by another electrode of some type. If the GEC and the bonding jumper are properly sized for the water pipe, I think 250.64 (F)(1) would allow the GEC to run to a ground rod first.
I also think that is the reason for the requirement for supplemental electrodes. I would bet the water pipe will nearly always provide a better electrode than a rod.
You can't bond the non-GE steel then jumper steel to water pipe. The bonding jumper to steel is bonding jumper, not a GEC... and the steel is not a GE so the jumper between it and the water pipe is not an electrode bonding jumper.
You could run a GEC by way of and bond it to the non-GE steel en route to the water pipe.
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