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Posted By: rharley Grounding EGC - 01/25/03 10:44 PM
Hello All, I'm hoping you can help me with some residential questions. I do mostly industrial and low voltage battery wiring and am a little confused about a service upgrade. I will be installing a 300 amp upgrade on my home. I will be bringing 3 250mcm copper from masthead into meterpan. I will have double lugs on the load side. 2/0ught will go 4 feet into bsmt to a 200 amp main breaker panel. #2 or possibly 1/ought will be pulled in the future in buried conduit to workshop out back 75 feet to a 100 amp main breaker panel.
Should the EGC from the 200 bsmt panel to the ground rods be #4 as per the 200 amp requirement or does it have to be larger as per the 250mcm feeding the meterpan? When I do the future run to the workshop I know I have to drive in 2 additional ground rods and treat that as a seperate service off of the meterpan and ground and bond accordingly. Also in Suffolk county, do the inspectors want to see a ground or bond run into the meterpan?? AT the 200 amp breaker panel I will ground to 2 rods outside as well as the street side of watermain and across watermeter. I'm just not sure of the EGC size needed at this stage because the other feed to the workshop wont be run just yet. I hope I don't sound like too much of a newbie, we don't have so much code confusion in the telco powerplant wiring. Thanks for any help.

Ron
Posted By: Redsy Re: Grounding EGC - 01/27/03 12:30 PM
The GEC is based on the largest service entrance conductor (in your case a #2). However, if you run it to the vicinity of the panel, you can tap it based on the main OCPD (which in the case of the 200-amp panel would be #4).
As far as your second panel located remotely, if you are not installing disconnects at the meter socket, there may be some question with regard to grouping of service disconnects. You should seek prior approval for your design.
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