splicing the ground

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westelectric

Senior Member
I have (6) 12/2 rx's entering a trough that is nippled above a panel. I would like to splice all grounds in a wirenut in the trough and tail (1) down into the panel and land it on the ground bar. Question: Is only (1) #12 ground enough?
 

RICK NAPIER

Senior Member
Location
New Jersey
A #12 would be code compliant. You size the ground based on overcurrent protection and increase its' size when current carrying conductors size is increased.
 

roger

Moderator
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Location
Fl
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Retired Electrician
Why use an 8 when i can use a 12. Im just wondering whats required. Can I find this in the code somewhere how to calculate whats required

A number 12 would be fine, the code reference is 250.122(C)

Roger
 

suemarkp

Senior Member
Location
Kent, WA
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Retired Engineer
I don't believe you can make any assumptions about the neutrals as far as which leg they are currently on and whether they cancel. I think you're going to have to add the current on each neutral to have one large enough. Only thing you can do is forget about the 125% continuous load factor, since it isn't terminating on a breaker.
 

lowryder88h

Senior Member
Location
Massachusetts
ground splice

ground splice

A number 12 would be fine, the code reference is 250.122(C)

Roger

Help me understand 250.122 (C), In the 08 NEC it says grounding conductor run with multiple circuits in the same raceway, cable, or cahle tray. Question the post refers to using (6) #12 NM's. To me its not compliant with 250.122 (C). I'm aleays ready to learn my mistakes, Thanks :D:D
 

Dennis Alwon

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Location
Chapel Hill, NC
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Retired Electrical Contractor
Help me understand 250.122 (C), In the 08 NEC it says grounding conductor run with multiple circuits in the same raceway, cable, or cahle tray. Question the post refers to using (6) #12 NM's. To me its not compliant with 250.122 (C). I'm aleays ready to learn my mistakes, Thanks :D:D
Basically what 250.122(C) states is if you have a raceway with say 20 amp and 40 amp circuits then you need to ground to the largest ocp. Thus a #10 wire would be needed. If they are all #12 wires then a #12 egc is all you need.
 

roger

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Location
Fl
Occupation
Retired Electrician
Help me understand 250.122 (C), In the 08 NEC it says grounding conductor run with multiple circuits in the same raceway, cable, or cahle tray. Question the post refers to using (6) #12 NM's. To me its not compliant with 250.122 (C). I'm aleays ready to learn my mistakes, Thanks :D:D

As Dennis said, the largest OCPD determines what size the EGC will be and if the largest conductor spliced in the group is a #12 (regardless of how many) on a 20 amp OCPD then a single #12 EGC is all that is required to the ground bar

Roger
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
For the neutrals I would get a isolated neutral bar kit and just install the neutrals there. You would not need any other wire for that.

Also if the ground bar is connected to the can then you don't need to worry about that either.
 

westelectric

Senior Member
For the neutrals I would get a isolated neutral bar kit and just install the neutrals there. You would not need any other wire for that.

Also if the ground bar is connected to the can then you don't need to worry about that either.

Re read post 1. The splice is in a trough nippled to the panel. I would need a neutral from the panel to splice of neutrals in the trough
 

kwired

Electron manager
Location
NE Nebraska
Re read post 1. The splice is in a trough nippled to the panel. I would need a neutral from the panel to splice of neutrals in the trough

The OP wants to terminate 6 equipment grounding conductors in the trough. If the trough and nipple to panel are metallic then they are approved EGC's and landing them on a terminal bar bolted to trough is all that is necessary. Paint removal at the terminal bar location is probably going to be required to ensure good bonding.
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Re read post 1. The splice is in a trough nippled to the panel. I would need a neutral from the panel to splice of neutrals in the trough
You can splice all 6 neutrals directly to the panel- No? Or is there no room to do this?

I am missing something. What is in the trough, just 6 NM cables? Are 3 the line and 3 the load? If there is a nipple just splice each wire thru.
 
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