I have an inspector that claims we do not need a ground wire for the following service. The service is a residential 400 amp, 120/240 volt, single phase that has the main breaker mounted in a free standing meter/combo that feeds a 400 amp main panel located approximately 700 feet from the main and is fed with parallel 250 mcm aluminum wire in 3" pvc conduit. The inspector claims we do not need a ground wire in the pvc conduit since the neutral is the ground wire. The meter/combo has a ground rod & ufer and the main house panel has a water pipe and ufer ground. Seems a little strange to me, what do you think?
Service Ground
- Thread starter 6506gary
- Start date
- Status
charlie
Senior Member
- Location
- Indianapolis
In my opinion, the 400 ampere circuit breaker has become your service disconnecting means and you are now running a feeder to the home. It would be better to leave out the service at that location and just install the cash register (meter). Driving a ground rod would be a plus but would not be required if it was installed without the service equipment. The grounding electrode would not be for grounding but would be for lightning protection.
If you leave the service equipment at that location, you will now be required to take four wires to the home and it is now the second structure. You are also required to set up your grounding electrode system at the cash register location and at the second structure (home). In this situation, the home would now have a down stream panelboard (sub-panel).
If you leave the service equipment at that location, you will now be required to take four wires to the home and it is now the second structure. You are also required to set up your grounding electrode system at the cash register location and at the second structure (home). In this situation, the home would now have a down stream panelboard (sub-panel).
tryinghard
Senior Member
- Location
- California
6506gary
Charlie is right you need a 4W feeder if this is under 2008 NEC but if it's 2005 NEC it may be okay as a 3W in the light of 250-32(B)(2), it is not a code violation to install a 4W on 2005 NEC though (and if in doubt).
It really is a feeder from the first 400A breaker and I agree with you because the rule is "A grounding connection shall not be made to any grounded circuit conductor [neutral] on the load side of the service disconnect", 250-24(A)(5) & "Except as permitted in...250-32(B), a grounded circuit conductor shall not be used for grounding non-current-carrying metal parts of equipment on the load side of the service disconnecting means", 250-142(B)
Charlie is right you need a 4W feeder if this is under 2008 NEC but if it's 2005 NEC it may be okay as a 3W in the light of 250-32(B)(2), it is not a code violation to install a 4W on 2005 NEC though (and if in doubt).
It really is a feeder from the first 400A breaker and I agree with you because the rule is "A grounding connection shall not be made to any grounded circuit conductor [neutral] on the load side of the service disconnect", 250-24(A)(5) & "Except as permitted in...250-32(B), a grounded circuit conductor shall not be used for grounding non-current-carrying metal parts of equipment on the load side of the service disconnecting means", 250-142(B)
- Status