Paralleled service neutrals

[George Stolz]

Perhaps some pictures would add to the discussion.

 

[karl riley]

George,
I am ashamed to say I don't know how to transmit a diagram.
Karl

 

[iwire]

George,
I am ashamed to say I don't know how to transmit a diagram.
Karl

Karl no need to feel that way...why would you have had to know that.

If you have a diagram in electronic format you can send to me (PM me for email address) or use a service like Photobucket a free photo hosting site.

 

[karl riley]

Bob, actually it's very simple. A parallel path for neutral back to the Tfrmr. One leg is the service neutral. The other leg goes down the GEC to the water pipe, out to the street main, then into a neighbor's water pipe to their GEC to their service panel, and back their service neutral to the same tfrmr. Pretty simple. Of course it can also use other neighbors' systems, but in my experience most of the exchange is between two houses.

Karl

 

[George Stolz]

As I post, I haven't re-read the thread to get back up to speed, but I thought there were two panelboards in an odd configuration in the same house, not the typical neighborly sharing of neutral load...?

 

[karl riley]

Right. Two SE cables enter the basement. The twin panels have the grounding bus bonded by a conductor underneath. The neutral and ground busses are bonded. The GEC to the rod comes from one panel, and the GEC to the water pipe from the other.

The SE cables are very short runs, maybe 2'. Each one has a high net current (19 amps when I measured) which means that much of the neutral from one panel's loads is going back on the other SE neutral, aside from the amount going to the water pipe path.

I was curious because I had not dealt with a situation where only one of the three conductors was paralleled.

Karl

 

[ramsy]

The SE cables are very short runs, maybe 2'.

Those are looking less like sub panels, perhaps no EGC bonds are needed between them, but I'd check with your AHJ before removing something they consider more important than objectionable.

 

[karl riley]

Roger, there was no intention to remove the bonds. This was just a side observation, not what the thread was about.

Karl