240 vs 480

[Raul600]

I am debating between using a 240 volt single phase electrical service or a 480 volt single phase for a large outdoor parking facility? What benefits do 480 services provide other than longer distances and less heavily gauged wires? Would maintenance be a problem? :roll:

 

[Cold Fusion]

I've never seen a single phase, 480V sevice. I'm sure somebody can point to one somewhere, but I can't think of why it would would have been installed.

cf

 

[Raul600]

480 single phase are used in roadway illumniation.

 

[charlie]

We provide 480 volt, 1? for use by INDOT (Indiana Department of Transportation) and DPW (Department of Public Works) but it is not available for other uses. :smile:

 

[realolman]

Any advantages to not doing it three phase?

Would this be just a single transformer with primary on one side, and 480 across the secondary?

Would there be a neutral?

What would be the voltage to ground?

Would any of it BE grounded?

Oops, I think I just passed my quota of dumb questions.
:smile:

 

[Raul600]

Any advantages to not doing it three phase? Can only use single phase due to public entinty prefers single phase.

Would this be just a single transformer with primary on one side, and 480 across the secondary? Yes

Would there be a neutral? Yes

Would any of it BE grounded? NO

 

[George Stolz]

Raul, please clarify your last post.

Some readers have heart conditions.

 

[Cavie]

Any advantages to not doing it three phase? Can only use single phase due to public entinty prefers single phase.

Would this be just a single transformer with primary on one side, and 480 across the secondary? Yes

Would there be a neutral? Yes

Would any of it BE grounded? NO

????????????????????????

 

[Raul600]

Sorry for the confusion, and thank you all for your time. Hopefully the following question will clarify everything.
Other than the 3 items listed below, what would be the benefits of using a 480 volt electrical service over a 240 volt service in illumination design?
(240/480 Single Phase typical for roadway illumination projects)

1.Smaller gauged wire

2.Longer conductor runs

3.Increased number of luminaires.

4.???

5.???

 

[Cold Fusion]

I think you got it. It's pretty much an accounting problem.

Although if you are going to use 480V single phase, look at 250.20, 250.21, and 250.30.

A single phase 480 panel is a strange duck. I don't recall seeing one of these either - wonder if anybody makes one.

I'm really surprised your customer won't entertain 3-phase. A normal install for this would be a 3ph service from the utility with 2-pole circuit breakers feeding each lighting circuit.

For a small install, or where the utility can't easily (read lots more money) supply 3ph is to just use 1ph 240V - pay for the fat wire

To use a 240V service, feeding a 240/480V xfm, I'm wondering where you want to ground the 480V. Any way you do it, it's a one-of-a-kind:
One end - that's kind of high, 480V to ground.

Center tap - 240V to ground, I guess that's better

Ungrounded - get the ground detection right,

We provide 480 volt, 1? for use by INDOT (Indiana Department of Transportation) and DPW (Department of Public Works) but it is not available for other uses.

Charlie -
When INDOT supplies 1ph, 480V, how do they deal with the grounding?

cf

 

[charlie]

. . . When INDOT supplies 1ph, 480V, how do they deal with the grounding? . .

We supply 240/480 just like 120/240 except twice the voltage. :smile:

 

[Cavie]

round here, 480v lighting is 480 2 wire. hot and neutral.