400' outlet. voltage drop?

[electricblue]

I gotta run an 120v outlet out 400' on a bridge. The volt drop calc says i need a #4 to #2. Can I buck the voltage up at the beginning and use a smaller wire?

 

[iwire]

I gotta run an 120v outlet out 400' on a bridge. The volt drop calc says i need a #4 to #2.

That sounds excessive.

What did you use as the load current for the voltage drop calculator?

Can I buck the voltage up at the beginning and use a smaller wire?

No, the problem with that idea is the 'no load' voltage will be too high at the far end.

You could send 240 out to the bridge which would cut the current in half and reduce the wire size. At the far end you would install a 240 to 120 transformer.

 

[infinity]

That sounds excessive.

What did you use as the load current for the voltage drop calculator?




No, the problem with that idea is the 'no load' voltage will be too high at the far end.

You could send 240 out to the bridge which would cut the current in half and reduce the wire size. At the far end you would install a 240 to 120 transformer.

I agree that a step down might be a better solution maybe even 480/120 if available. I'm wondering, for a bridge what would you use as the grounding electrode for the derived neutral?

 

[electricblue]

I did 20amp for the load. I can't put a tx at the end. It would not last very long that close to saltwater. It's a concrete bridge. I'm gonna go get clarification on the specific load.

 

[iwire]

I agree that a step down might be a better solution maybe even 480/120 if available.

If 480 was available I would use it for sure but I assumed his max available voltage was 240.

I'm wondering, for a bridge what would you use as the grounding electrode for the derived neutral?

The devil is in the details as always, I was picturing having to put the transformer, GES and OCPD near the bridge not on it.

 

[electricblue]

I always leave out details. It's most likely 208 or 240 volt. It's on the beach. Sucky place to work...

 

[iwire]

It's on the beach.

Oh. That really complicates things.

I might just pass on that job.

 

[zbang]

I did 20amp for the load.

For a 20a circuit? Without knowing the actual load, wouldn't 16a (80%) be more correct for that? Probably doesn't make that much difference for this.