Wire for a 480v 3p run of 800 feet?

[thane]

I have an opportunity to get some cable at a great price.

It's 3 conductor 10 awg. Direct bury, armored.

I need to run 800 feet from turbine to batteries... will this work?

I don't have the turbine yet... Will I need ground or neutral?

[wooferhound]

How many amps do you think you will be pushing through this wire run ?

the voltage doesn't help much . . .

[thane]

I think I will be limited to about 8 amps... no?

[ghurd]

The turbine will determine if it is suitable.

It would be OK for a very low power turbine,

Or a high voltage turbine,

Or a high voltage AC turbine being transformed to a lower voltage near the battery,

Or...

That 800' is a long ways to run.  #10 is not very big.

G-

[wooferhound]

According to the voltage loss calculator on this page

http://www.powerstream.com/Wire_Size.htm

you would lose about 14 volts on a 800 foot run of two 10 gauge conductors pulling 10 amps.

If the armor is conductive you could pair up 2 conductors of your cable for the Positive side, and the last conductor plus the armor for the Negative side. This would halve the voltage loss.

I have the Negative side of my Solar Power grounded but it is not necessary. If your turbine is 3 phase you may rectify and combine the phases onto 2 wires before you send the power on the 800 foot trip, or you could send all 3 phases down the 800ft line which will require 4 conductors. That may work if your armor on the cable is conductive.

 

[Airstream]

Wire run calculates to 2.96% voltage drop at 10 amps, a nearly perfect spec. With 5 amps the drop is half that.

True 3 conductor will have three 10's and a ground. If you are seeing 2 10awg and a ground wire check if the ground is the same gauge as often they reduce its size.

What I am hoping to hear is the cable is NEW and UNUSED, it would be hard to justify the labor of burying 800' of used cable because of possible future problems. If it is used and cheap enough there is always PVC conduit...

480V means it will always be searching for any excuse to leak & short possibly with much less 'cause' than with lower voltages.

[thane]

Yes, it's new.  I may be able to get a "LOT" of it... enough to run multiple legs.

[Airstream]

:::drool:::

[wildbill]

cheap it dosn't burn your fingers when you pick it up,#10 under ground big bucks.

good find.

[dnix71]

Whoever is selling you the turbine should be responsible for wiring it to code.

480v ac is immediately lethal. There were some unfortunate people at bus stops in Miami a few years back that fried because some asshat contractor couldn't properly ground the 480v step down transformer used for lighting the bus shelters.

The ground there is solid coral limerock. You can't drive a ground rod in it, and even if you did, rock doesn't carry away stray current very well.

http://www.justnews.com/news/4444128/detail.html

http://www.justnews.com/news/4441192/detail.html

He was not licensed and the county did not require a license or permits or inspections.

Do yourself a favor and demand a licensed, inspected job.

[thirteen]

As a safty thought if you are the only one working on the system and you understand 480v 3 phase it would probably be ok. But if there is a chance someone else will work in it please label it correctly. A simple lock on a power box may help. No insult intended. Alot of people don't uinderstand it and it kills in a heart beat. I work with it every day and it is dangerous. Just as an idea.

[FUEL]

I don't know what the code is in your area but with only 8amps it should be fine. if it's cheap it would not hurt to run more then one, for possible future use.  i'll run 2#10 for A/C's running on 220v 20 amps, it all depends on the how long it is and amps really. here's a good calculator

http://www.jhlarson.com/ind_tables/volt/calc_wiresize.htm

And on the safety side, VOLTS don't kill, AMPS do. you can get a sapped with 10,000 VOLT , like in a tazer and be fine but get zapped with 30V but only 0.5AMPs and your done. now it's not to say volt doesn't play it's part but it just pushs amps trough you, the less resistance in you (IE: being wet, grounded, very high salt diet, ect) the easier it is. it takes something like 0.70mA to stop your hart.

sorry, they drive safty into us at work

[Opera House]

A lot of farmers were killed with Delco 32V 30Hz generator systems.  As frequency goes up there is less tendency to grab on.

[WindJuggler]

Hello,

Nice cable. I would say always use a ground and label properly. If there is no ground-wire available use the shield or armor.
Using a neutral depends on the type of generator you use. If it has a neutral use it and wire it properly if not don't use one.
10 awg should be enough. The losses are low at high voltage/low amps. Bear in mind that the current output of 3phase is equal to 2phase divided by square root of 3. So if the total current output is 8 amps in 2 phase or after rectifying then the current trough 3 wires would only be 4.61 amps. For this 10 awg would suffice for sure.

By my calculations (8 amps per phase) it would be a 6kW machine. That's a lot of power. Nice.