Electrical upgrade advice/thoughts

[jack duren]

I'm not real sure what you're asking Charles, but I believe his intent is to install a new 60 amp feeder to a new breaker panel, located in his separate structure. If that is indeed the case, then it would require a separate grounding electrode system installed according to article 250.32(A), and part III of article 250 of the NEC.

I assume he's feeding off the original panel from the source which is already grounded. If this is the case he's already grounded.

[David Castor]

If this is the case he's already grounded.

That may be, but the current NEC (250.32) requires "buildings or structures supplied by feeder or branch circuit to have a grounding electrode. As noted previously, there is an exception for a building fed by a single branch circuit. But if a sub-panel is to be installed in the shop building, that exception doesn't apply. A ground rod is needed to meet the current NEC. This was not always the case, but has been a requirement for a number of years, IIRC.

The price seems a little on the high side, but not excessively so. You may want to get another quote.

[Matt Marsh]

I assume he's feeding off the original panel from the source which is already grounded. If this is the case he's already grounded.

Any separate building/structure requires it's own grounding electrode system. The existing grounding electrode system at the structure where the feeders originate will not satisfy the requirements of article 250.32(A) for the separate structure. Again, the only exception is when that building/structure is fed with a single branch circuit (including a single multiwire branch circuit). In this case the exception does not qualify, because it is not being fed by a single branch circuit, it is being fed by feeder conductors, supplying a branch circuit breaker panel.

Do not confuse the terms grounding and bonding. If these feeders originate at a main panel in another structure, they must be accompanied by a properly sized equipment grounding conductor. This EGC must be terminated in a auxiliary grounding bus in the new breaker panel, and it must be kept isolated from the neutral conductors (do not install the main bonding jumper screw in the neutral bus). The grounding electrode conductor should also terminate at the auxiliary ground bus. This auxiliary grounding bus is most often a separately purchased option.

[Abe Music]

Hey all, my apologies for not being active on the thread I started...apparently I had my notification settings relaxed or something. At any rate, I thank all of you for your input.

Some updates:

I've noticed some discussion around ground rods and such and I've already got the ground rods on the detached building. Next weekend we're going to try to disconnect the existing cable and see if it can be pulled through...if so, then it should certainly remove any major complexities in the job.

Also, I had a second quote come in at over $2000 and that was for pulling #6 (IIRC) for 60 amp service and installing a surface mount box That just seems soooo expensive. I'm visiting my wife's family right now and her uncle is a contractor with appropriate licenses for a different state, but he said this is not a job he would personally pay that much for. He's offered to come down in a couple months and help me do the job if I supply the materials. I'll need to check with local codes to see if this is something I can do as a home owner or if I'll need an inspection before/after.

An additional update that's interesting and I may end up going for is I spoke to the electric company about adding a 200amp service to the detached garage. I would be required to trench, supply 3" schedule 40 along with an appropriate pull rope, and the disconnect. They would supply the cable and labor to pull it and attach it up. I could then add my panel inside and basically be future proof for anything I'd like to do in there (like maybe adding a small heat pump for when I finish out the attic and move my home office there.)

[Abe Music]

It's in Mount Juliet, but your idea is something I'm certainly considering. I will need to check on the local codes for this, but at my last house I was able to do my own work without issue.