Equipment Grounding Conductor

[GoldDigger]

Let put an argument back on you...

If a parallel run of 8 conduits will permit any one failure point, why do we have to run 8 full-size EGC's when we run a wire-type EGC? Why can't we just run one full-size and be done with it?

Well, my guess is that the CMP was considering at least two situations:

1.The fault current will be higher and more likely to promptly trip the OCPD if the return path (EGC) is in the same ferrous raceway as the conductor feeding the fault. Especially if the fault is within that one raceway a single EGC in another raceway may not offer as low an overall impedance.
2. If you have N parallel runs and need to service one, knowing that only one of the runs contains the EGC and that you therefore need to preserve it while doing the rest of the work is not a given down the road.

 

[Smart $]

Well, my guess is that the CMP was considering at least two situations:

1.The fault current will be higher and more likely to promptly trip the OCPD if the return path (EGC) is in the same ferrous raceway as the conductor feeding the fault. Especially if the fault is within that one raceway a single EGC in another raceway may not offer as low an overall impedance.
2. If you have N parallel runs and need to service one, knowing that only one of the runs contains the EGC and that you therefore need to preserve it while doing the rest of the work is not a given down the road.

Not only are we not on the same page... I'm thinking we're in completely different books. :lol:

 

[infinity]

Let put an argument back on you...

If a parallel run of 8 conduits will permit any one failure point, why do we have to run 8 full-size EGC's when we run a wire-type EGC? Why can't we just run one full-size and be done with it?

Maybe Copper.org?

 

[GoldDigger]

Maybe Copper.org?

Now that is a book we can probably all agree on. :lol: