Not sure what size required

[Oldmaster2]

Have a pvc conduit with six #12 conductors. It goes from j box to panel. I'm thinking I only need to run 1 #12 for ground. Is this correct?

 

[bwat]

What's the largest size breaker ahead of those wires? 250.122

 

[Oldmaster2]

20 amp

 

[bwat]

Then yes, it sounds like you're good by running a single #12 copper. See 250.122(C) and Table 250.122

 

[LarryFine]

A single EGC sized for the largest OCPD may be used for all circuits, even a whole panel's worth..

 

[infinity]

In this case the breaker size is probably irrelevant.

 

[bwat]

In this case the breaker size is probably irrelevant.

Probably

 

[petersonra]

A single EGC sized for the largest OCPD may be used for all circuits, even a whole panel's worth..

Most people do not get this because they are all worried about not having an EGC for each circuit for some reason. There has to be an EGC wired with all circuits but it does not have to be an individual EGC for each circuit.

 

[Jerramundi]

Most people do not get this because they are all worried about not having an EGC for each circuit for some reason. There has to be an EGC wired with all circuits but it does not have to be an individual EGC for each circuit.

Dare I say that the day will probably come where it's one circuit per conduit?

Out of curiosity, I have to wonder what would happen if multiple circuits in a single raceway with only one EGC grounded out and the EGC wasn't capable of carrying the load for all the circuits. Would it just be a successive shutting down of the breakers one by one? As one tripped the EGC would allow the next and so on and so forth?

 

[petersonra]

Dare I say that the day will probably come where it's one circuit per conduit?

Out of curiosity, I have to wonder what would happen if multiple circuits in a single raceway with only one EGC grounded out and the EGC wasn't capable of carrying the load for all the circuits. Would it just be a successive shutting down of the breakers one by one? As one tripped the EGC would allow the next and so on and so forth?

Where using a common EGC it has to be sized for the highest rated OCPD so not a problem. Its not like there is any likelihood of multiple simultaneous ground faults.

 

[Jerramundi]

Its not like there is any likelihood of multiple simultaneous ground faults.

Unlikely yes, but not impossible. It's also unlikely that, generally speaking, when troubleshooting an issue, the apparent single issue is actually two separate problems occurring simultaneously, but logically it is still a possibility.

I had a hot tub connection fail simultaneously with a dishwasher in the kitchen. Really made me scratch my head. But turned out to be two separate issues occurring simultaneously... (1) loose breaker for the hot tub (2) loose connection at the DW. I guess I'm just lucky, haha.

I'm just musing. Don't wanna hijack the thread.