new panel

[Jeff Rae]

I'm feeding a panel 120/208v. from a breaker in a meter stack. The meter stack is supplied by a 400 amp. breaker where the ground and neutral are bonded. Do I need to run a 4 wire ckt. and also another ground rod or 3 wire and bond the neutral and ground also to a ground rod. THANKS

 

[raider1]

Are you talking about a panel at a seperate structure?

Chris

 

[eric stromberg]

Jeff,
You are always better off running a separate neutral and ground. Even if this is a separate structure where it is currently legal to run a single conductor for both neutral and ground, it is not a good practice and may even be overturned in the 2008 Code. (Stay tuned).

Eric Stromberg, P.E.

 

[eric stromberg]

Jeff,
Obviously, if it is a service disconnect, the neutral is required to be bonded. If it is a subpanel, the neutral should not be bonded.

Eric

 

[iwire]

Jeff,
You are always better off running a separate neutral and ground.

So we can not use the utility service anymore? :wink:

What makes it different on the load side of the service disconnect? :? (As far as separate structures are concerned)

Lets say a 200 amp service disconnect is on a pole at the street and the run to the home is 500'.

Is it really better to run an EGC?

Wouldn't the impedance of the ground fault path be higher using the NEC sized EGC than the larger grounded conductor?

I have never used 250.32(B)(2) but I can imagine instances where I would.

Just some items for discussion.

 

[electrofelon]

I think the major argument against (B)(2) is that a metallic path could be added in the future thus bringing the whole system into violation and resulting in differences of potential between two nearby objects. I personally use (B)(2) whenever I can. We Americans already use way more than our fair share of resources and energy.