3 or 4 Wires

[CIECO]

I have a 500? overhead run to a temp trailer. 120/240 volt. Do I use 3 wires and ground rod or 4 wires and a ground rod?

 

[jumper]

I have a 500? overhead run to a temp trailer. 120/240 volt. Do I use 3 wires and ground rod or 4 wires and a ground rod?

This is a feeder, right?

If so, 4 wires and a GES I think.

 

[infinity]

What code cycle are you under? For the 2005, I'm guessing that 3 conductors may be all that's required if 250.32 applies.

 

[CIECO]

That is what I think but I am not sure? (05) Look at 250.32 (1) & (2)

 

[cripple]

3 or 4 Wires

It would depend if the temporary service in the design and under what Code cycle it was approved. If the temporary service is not in the design it would have comply with the current Code.

 

[jumper]

That is what I think but I am not sure? (05) Look at 250.32 (1) & (2)

Go back and read 250.32(B)(2).

Like Infinity said, do you comply for this section.

This section is not in the 08. All 4 wire and a GES, except for existing installs.

 

[CIECO]

Thank you.

 

[jetlag]

I have a 500? overhead run to a temp trailer. 120/240 volt. Do I use 3 wires and ground rod or 4 wires and a ground rod?[/QUOTE


It looks like exhibit 250.17 in the NEC handbook only shows 3 wire for the feeder from panel in one building to panel in another building there is a neutral but no EGC but each panel has a ground rod. That is very confusing because a mobile home fed from a disconnect on a pole requires 4 wire with ground rod at disconnect but not at trailer panel

 

[CIECO]

I ordered the 4 wire just to be sure. But I still think 3 wire and ground rod are ok.

 

[jumper]

I ordered the 4 wire just to be sure. But I still think 3 wire and ground rod are ok.

Unless you are going to test for 25 ohms or less, I think you need 2 rods.