brantmacga
Señor Member
- Location
- Georgia
- Occupation
- Former Child
Have a project where the plans called for “dedicated ground” on a few circuits. Each circuit itself is dedicated, using MC cable back to the panel. As in, there is either duplex or quad in the box, and single run of 12/2 MC back to the panel. Metallic boxes, but 100% wood framing. Original drawings did show steel trusses and demising walls but changed to wood due to steel lead times.
This tenant space has Panel A, which is a 225/3 sub-panel with 4-wire feeder off the exterior disconnect, and panel A2 which is a 100/3 fed from Panel A.
I reviewed the drawings when asked by the job foreman and saw there was no isolated ground bar specified in either panel, so to me, a dedicated circuit that doesn’t share a ground with other circuits is indeed a dedicated ground. There is no grounding path between any other circuit and the “dedicated ground” circuit other than they share the same grounding bar.
In my opinion the engineer should have specified “isolated ground”, listed an IG ground bar in each panel as both have “dedicated ground” circuits, and required a 2nd EGC in the feeder if they indeed wanted an isolated ground.
What do you think? Lesson for me, or lesson for the engineer?
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This tenant space has Panel A, which is a 225/3 sub-panel with 4-wire feeder off the exterior disconnect, and panel A2 which is a 100/3 fed from Panel A.
I reviewed the drawings when asked by the job foreman and saw there was no isolated ground bar specified in either panel, so to me, a dedicated circuit that doesn’t share a ground with other circuits is indeed a dedicated ground. There is no grounding path between any other circuit and the “dedicated ground” circuit other than they share the same grounding bar.
In my opinion the engineer should have specified “isolated ground”, listed an IG ground bar in each panel as both have “dedicated ground” circuits, and required a 2nd EGC in the feeder if they indeed wanted an isolated ground.
What do you think? Lesson for me, or lesson for the engineer?
Sent from my iPhone using Tapatalk