ECN Forum Forums General Topics of the Trade General Discussion Area 400 amp service

I am helping a friend install his service and ran into a situation that I'm not sure about. He bought GE circuit breaker enclosures, no.TQD200NRE to use as the disconnects to each of his two panels. Inside the enclosure is the breaker and the grounded and grounding lugs. They are one and the same. It is a one peice lug with a place for the netural and a place for the ground. The netural and ground is bonded inside the meter base. Would this not be a viloation if I wire the disconnect the way it looks like it is meant to? Could I not use the ground termnals and install a double lug inside the can for the grounds. This is made up with pvc. Hope this make sense.

Keith

Sorry but I don't understand all the details.

If you wanted the equipment ground seperate from the nutral then you need a ground bar kit.

If the service panels are the first disco then the equip ground would go to the nutural. If you have more then 1 panel serving as the service disco the all would have the equip. ground on the nutural.

We don't use non metalic for our services so I can't be of more help.

Tom

You can forget about the bond in the meter socket it is allowed by 250.142(A) And it is need to bond the meter enclosure.

And strangely no matter if you have one or six service disconnects each and everyone is required to be bonded. 250.24(B)

The standard around here is a bonded meter base, PVC service entrance cable raceway, 3 insulated conductors and bonded neutral/ground in the service disconnnect enclosure. There will be no parallel path for the neutral this way. It becomes a little more dicy when you have a metal raceway and most inspectors here call that a parallel neutral. I have heard others say it is not an issue.

Keith, I understood your question, and here's a simple answer:

The first (main) disconnect (breaker, in this case) is exactly where the neutral and ground are to be separated. The incoming cable contains two hots and (typically) a bare: the service-cable neutral.

However, the outgoing cable should contain two hots, an insulated neutral, and a separate bare; the equipment grounding conductor. This is because the neutral and ground must be separated beyond the main disconnect.

So, all three conductors (the incoming bare, the outgoing bare, and outgoing insulated neutral) should be connected to this neutral/grounding terminal block. Be sure that the enclosure is bonded to this block, too.

Sometimes, the block is bolted directly to the enclosure already, and sometimes you must install a screw or jumper, like in a main-breaker panel. The interior breaker panels do not require main breakers; you can use main-lug panels.

In addition, the breaker panels must NOT have this jumper or screw installed, and you may need to add grounding strips, if there are not separate neutral and ground busses already. By the way, these panels are now actually sub-panels.