Cajun technology?

[wirenuts]

Hi all....

i have an interesting individual, living a good distance in the woods away from power on a propane genny.

in soliciting power, a poco rep told him a wire(s) size he did not like, as well as some $$$$ that followed, so he is now building a shed near the road for quick power.

as in many localities, the poco really does'nt mind what one does past the main disco..........so this man decides that he'll purchace two x-formers, boost up the voltage at the road, step in down at his cabin....

i suppose that this may be done , and is done given x-former costs vs. wire size, yet it seems inefficent in terms of core loss, etc.

please keep in mind we are @ $ 0.117 a KWH here, and my first reaction was the percentage wasted.

anywho...

what factors would contribute to a more efficent configuration of said x-formers?

any concerns/ opinions/ poco rants appreciated....

P.S.~ a quality forum as always Warren !

[Wgoodrich]

Thanks for the good thought wirenuts.

A transformer is 99 % effecient. No loss factor should be of concern in using the transformers.

I would need the distance and load involved before we could come down to some numbers but it really is not a bad design to boost power then drop power. Best move is to do your research as to what the power company will provide. In this area we can get 480 volt single phase that would allow you to go as much as 600 feet without voltage drop concerns normally.

All depends on demand load at the cabin and the voltage available at the power company.

I have designed some off road projects that took an accepted 7,200 volt primary metering allowing almost unlimited distances.

Give us the demand load at the cabin and the distance from power meter to cabin then we can get down to the fun of it.

Before he commits try and find out what voltages he can get from the power company. Tell him to mention field irrigation and other projects far off the road. Then we can play the power up and down as we need the design for the load to match.

Curious

Wg

[wirenuts]

ok.

the poco will simply provide a OH service at his roadside shack ( were he sells maples suyrp) , i guess there's some bad blood bettween this dude and the poco, as they apparently will not entertian much more than this.
:roll:

the 'cabin' , in effect is his families home. right now it's run off 2 genny's, a swivel type solar collector, a bank of deep cycle batteries and a Hart engeneering inverter. The major appliances are LP gas, but the square footage, outbuildings, etc all are of normal housing quantity. It would be a 100A poco minimum in any case......


he would be approx 800' ( give or take, a good # to play with) from the powered shack, i believe the poco will do 100A 240/120 typical OH there & main.

inbettween he has a logging operation, a lot of ledge, and a rise up to his home.....no irrigation per se', other than run off, and the usual logging mess.....

i did not realize X-formers are as efficent as they apparently are, i had figured some loss
having dealt with/witnessed many rather warm ones ......so perhaps i've made an issue where there is none??
:oops:
anyways, here's a start, check me out please
( you'll probably recognize Mike Holts software here....)


480/240V x-former
cu,
75c thw/rhw/use ,
75c term rating,
pvc conduit,
1 ph AC
@ 800'..

480v
50a
800'
#2 cu will amount to;
3.16% vd
15.2 or volts lost




i suppose that beats the #500kcmil in 4" ....? :?

[Wgoodrich]

An article explaining voltage drop calculations can be seen on our homewiring web site below.

http://www.homewiringandmore.com/homewiringusa/2002/definitions/voltagedrop/voltagedrop.html

If you calculate 800 feet feeder 240 volt with 2 awg copper you would have a voltage drop of 12.9% or 31 volts dropped or end of line voltage of 208.9 volts.

If you up sized to 2/0 copper parallel you can get the voltage drop down to 3.22% or 7.7 volts dropped or 232 volts at end of line without installing any transformers.

If you used a step up and step down transformer then you could use 240 volts stepped up by transformer to 480 volt run for the 600 feet then step back down from 480 volts to 240 volts and using a 2 awg copper conductor at 480 volts for 800 feet would provide you with a voltage drop of 6.5% or 31 volts dropped or 449 volts at end of line computed to 224.5 volts on secondary side of the transformer at the cabin with a voltage drop of 6.5% voltage drop or 15.5 volts dropped.

Wirenuts, now you should be able to take the above date and compare the larger wire being 2/0 parallel calling for approximately 1600 feet of 2/0 single copper USE conductors per hot conductor and say a 4/0 estimated single neutral conductor 800 feet long to make up your feeder to your remote cabin.

Compared to two 100 amp rated transformers 240 / 480 volt using one 2 awg three wire use cable with the three conductors in your cable.

Let us know what your caparitive cost figures are comparing the transformers and smaller wire or the parallel 2/0 cables as your feeder.

Curious

Wg