How do you comply with exception no.1 of 250.32(b)(1), requirement (2) for existing buildings supplied by feeders without an EGC? If you must also install a Grounding Electrode at the panel being supplied by the feeders, wouldn't that always create a continuous metallic path to the grounding system, because you must create one?
How do you comply with 250.32(b)(1) Ex no.1?
- Thread starter BenG
- Start date
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Are you asking about a feeder to a separate structure that does not have an EGC? If so you would bond the neutral and run a GEC to the GES.
Wouldn't doing that no longer comply with the exception? Particularly, requirement 2 that states "There are no continuous metallic paths bonded to the grounding system in each building or structure involved."
- Location
- New Jersey
- Occupation
- Journeyman Electrician
The "continuous metallic paths" would be something like a metallic water pipe, phone line, CATV, etc. If none of those exist it is permitted to use an existing 3-wire feeder without an EGC and bond the neutral at the separate location. For a new install you'll need a 4-wire feeder.
I see. Follow up question then. Does this rule only apply to a separate structure? Would this apply to feeders on the load side of an outside Main Service Disconnect that's attached to the same building? The feeders are run in underground PVC underneath the building, which would be considered outside the building, and then stub up into a Main Distribution Panel inside the building. I would think that because they are no longer Service Conductors on the load side of the Main Disconnect, they become Feeder Conductors, and "250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s)." would apply?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Yes it (no EGC) applies to existing separate structures. It may also apply if what you're calling the main servcie disconnect is set up as the emergency disconnect, not service equipment and so marked. {230.85}
230.85 mandates emergency disconnects for residential applications. This is a commercial building. This disconnect is directly adjacent to the meter though. Even though it's not required to be one, you're saying if this Disconnect is considered and marked as an Emergency Disconnect, 250.32(B)(1) Ex no.1 may still apply?
Or just the standard practices, because the load side conductors of an Emergency Disconnect are still considered Service Entrance conductors?
Thank you!