DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   400 foot electric (http://www.diychatroom.com/f18/400-foot-electric-76716/)

Bgm94 07-20-2010 09:34 PM

400 foot electric
 
what would be the most cheap and efficient way to run electricity to a shed about 400ft away (100 meters) continuously? I will, for the most part, be powering lights and maybe a drill (MAYBE).
Thanks
Bill

nap 07-20-2010 09:42 PM

define cheap.

As I define cheap, there is no cheap method to get power 400 feet.

other than that, some large cable (#2 cu or 1/0 al)

Yoyizit 07-20-2010 09:47 PM

A 5% drop at 6 A at 120 V allows 1 ohm max. For an 800' round trip with copper, for just voltage drop considerations, it's #8 or thereabouts, but most people advise you'll be asking for more power later.

Bgm94 07-20-2010 09:51 PM

could someone please link me to what i need, and what i need to do exactly

nap 07-20-2010 09:52 PM

Quote:

Originally Posted by Yoyizit (Post 472697)
A 5% drop at 6 A at 120 V is 1 ohm. For an 800' round trip it's #8 or thereabouts, but most people advise you'll be asking for more power later.

so you are suggesting a 6 amp breaker?

If he is going to run a 20 amp circuit, he should use large enough wire to carry most of the circuit capacity.

and at a 6 amp load you would need #6 (cu) to remain below the recommended 3% voltage drop.

Since we are talking about a drill (electrical motor) the start current is going to be considerable higher than the running current.

Yoyizit 07-20-2010 09:57 PM

Quote:

Originally Posted by nap (Post 472704)
the start current is going to be considerable higher than the running current.

That motor surge seems to be incorporated in the 3% or 5% limit, the so-called supply "stiffness."

nap 07-20-2010 10:12 PM

Quote:

Originally Posted by Yoyizit (Post 472707)
That motor surge seems to be incorporated in the 3% or 5% limit, the so-called supply "stiffness."

Huh?


current is current. If current goes up, it will cause a greater voltage drop.

Stubbie 07-20-2010 11:17 PM

You pretty much have to figure a 120 volt circuit at 800 feet round trip and you need to figure 20 amps in my opinion to do what the Op wants. If you consider a 20 amp multiwire circuit there would be some benefits to VD but you will need to practice load balancing on the hot legs.
Just the same the wire needs to be large enough to handle 20 amps calculated on a 120 volt circuit.

The distance creates a few problems due to wire size and possibly the biggest is the cost of the wire depending on the OP's budget.

That wire size is likely to put you into a pvc conduit wiring method with thwn wires.

Anyway I don't see 'cheap' in getting 20 amps 400 feet. There are several things that need to be considered when you have to upsize wire for that kind of distance to kill the VD.

To get to 'cheap' you might be better off to move the shed closer to the supply point ... say about 200 feet......:)

frenchelectrican 07-21-2010 12:51 AM

for little over 100 meter you denfine need at least 35mm˛ { #2 CU } or larger conductors that for a single 20 amp circuit.

The other issue will come up very fast here is the termation try to go from 35mm˛ to 4.0mm˛ { #12 AWG } to hook up the breaker you will need either split bolt or polairs tap connector block.

And yeah you will need oversized junction box at the shed side but for house side if you are landing at the load centre it is not too bad.

Also if you want to go with alum verison you have to bump up one size larger.
They are little cheaper but how much it depending on what it have on stock and what specal order.

Merci.
Marc

Jim Port 07-21-2010 08:17 AM

Nap, the so-called supply "stiffness." is the opposite of voltage droop. It is caused by using a blue conductor. :laughing:

Please get help if this condition lasts longer than 4 hours.

nap 07-21-2010 10:00 AM

Quote:

Originally Posted by Jim Port (Post 472845)
Nap, the so-called supply "stiffness." is the opposite of voltage droop. It is caused by using a blue conductor. :laughing:

thanks Jim. I must have missed that in my apprenticeship.

Proby 07-21-2010 10:57 AM

Normally for detached garages I like to install 100A sub panels, or at the very least 2X 20A circuits. However, sometimes the homeowner truly does only want a light or two and a battery charger or drill.

A 100A sub panel at 400' wouldn't work out too well for the thread starter :laughing: As long as his drill is variable speed, maybe he is alright with just running 8-2 UF cable :whistling2: Altho it's still no where near "cheap" :wink:

Scuba_Dave 07-21-2010 11:11 AM

Actually if you run #6 wire for a 20a 240v small sub that will work
Voltage drop 3.2%

Or a 30a sub would work with #4 wire

forresth 07-21-2010 04:53 PM

to be honest 400' of any wire wont be cheap, move your shed closer

if you really only want to run a couple of incandecent lights, I bet even 12 gauge would do. Everyone always talks about the 3% drop standard, but I bet the OP could get by with a 25% VD. the bulbs will be a little dimmer and the drill will turn a bit slower, but it will all work.

I think we've all played the lets see how many extention cords we can string together at one time or another, and for the most part the stuff at the other end still works. I've never taken it 400' but but I have run a cememnt mixer with about 200 feet of cord before, and that coming from a house thats a bit low on voltage to begin with because its a ways from the transformer. 12 gauge is heavier than the standard extention cord.

run 8x 50' extention cords together as a test if you want first. either way, you'll be set for outdoor extention cords. :thumbup:

Speedy Petey 07-21-2010 05:23 PM

Quote:

Originally Posted by Bgm94 (Post 472703)
could someone please link me to what i need, and what i need to do exactly

Hire an electrician. :thumbsup:

www.electrician.com


All times are GMT -5. The time now is 09:14 AM.


Copyright © 2003-2014 Escalate Media LP. All Rights Reserved