525 ft wire run

[JLCELEC]

Let me see if im nuts or correct about this. Here we go. I have a main distrubution feeder approximately 525 ft away. I have to run a 100 amp feeder service to a load center in a barn. There going to start having weddings there.. Anyway when i do the voltage drop calculation i come up with a wire size of 4/0 copper. Am i doing this right? Here is my calculations. vd=2k x L x I divided by the circular mills.

CM =211600
AMPS =100
LEGNTH 525 FT

2 x(12.9) x 525 x 100amps =1354500
CM =211600
1354500 /211600 =6.401 volts / 240 volts=2.67% voltage drop..
Let me know if i am correct. I apprerciate all of youre help.

 

[wolfman56]

Checked it on my ElectriCalc Pro, your good.
However you may be better off calculating the highest possible load used and go with that.
For example you could give it 80 amps and then feed it with 4/0AL and save some dough.
Rick

 

[JLCELEC]

Thanks Rick i appreciate the quick response and help.

 

[kbsparky]

What will be your nominal load? I'd be willing to bet it ain't nowhere near 80 or 100 Amps.

Just because you have a 100 Amp panel does not mean you have to perform V/D calculations based on a 100 Amp load.

It won't be the end of the world if the V/D exceeds 5% for a few seconds, either.

 

[Sierrasparky]

What will be your nominal load? I'd be willing to bet it ain't nowhere near 80 or 100 Amps.

Just because you have a 100 Amp panel does not mean you have to perform V/D calculations based on a 100 Amp load.

It won't be the end of the world if the V/D exceeds 5% for a few seconds, either.

Just a little light fliker... or ?

 

[iwire]

What will be your nominal load? I'd be willing to bet it ain't nowhere near 80 or 100 Amps.

Just because you have a 100 Amp panel does not mean you have to perform V/D calculations based on a 100 Amp load.

Normally I would be with you but the OP says

There going to start having weddings there..

That could mean anything from nothing to bands, to catering equipment. All I am saying is that if this is going to host functions he may want to plan for the worst.

 

[LarryFine]

In the future, if they decide they need more power, they could always use a pair of transformers to step the voltage up for the distance.

 

[dbuckley]

... to bands...

Yes, all the lights dip on the beat of the music, hmmm... surely it can't get any worse...?

... catering equipment.

Oh yes, the caterers...

When they pop up a big tent next to the barn and fill it with two trucks of equipment, and then come looking for power, usually with orange or yellow extension cables that show signs of overheating through overload. Sure its OK to put four urns on a single cable. "everything on this table plugs into that"...

Be wary, and make sure that the owner knows what capability you are delivering.

 

[JLCELEC]

My fear exactly. But i know when i send over this proposal someone may have a heart attck.. LOL

 

[petersonra]

In the future, if they decide they need more power, they could always use a pair of transformers to step the voltage up for the distance.

It would not surprise me at all it was more cost effective to include a couple of transformers to kick it up near 600V so you can downsize the wire.

It might actually be more cost effective for the owner to rent or maybe even buy a mobile generator for power as needed. There are some that are pretty quiet.

You might even consider asking the local utility company. Sometimes they are cheaper than doing it yourself and other times they are horrendously expensive.