Here is an NEC ampacity chart:
http://www.okonite.com/engineering/nec-ampacity-tables.html
Note that you would want the figures in the 2nd from the left column, up to 3 copper wires in conduit. 8 gauge should be ok since it's just a 40 amp circuit, but keep in mind that normally you have to go up a gauge for every 100' of run. In other words, if you wanted a 50 amp circuit and saw that 8 awg is good for 50 amps, a run of 150' foot should go to 6 awg. Exceed 200' and it would have to go to 4 awg... just a thought for future reference. Also remember that since this is outdoor and running pumps for water features, your individual circuits should be on GFCI breakers. Also, by code, you should either have a separate gnd wire back to the main box, or a separate gnd rod tied to the gnd at the small box and the box neutral should not bonded to the ground. Just a little extra info in case you have to get a permit and have the box inspected by your local authorities. NEC is very specific about keeping grounds and neutrals apart in a situation like this.
Good luck!
- James
Thanks Greg,
You've got it. That's exactly what I want to do. I want to install a breaker box at the site and send power to it from the bigger box in my shop. That way, I can install several outlets for the layout, the pumps, lighting, and anything else I come up with. Thank you for your input. You've helped me more than anyone else I've asked.
Digger Dooley
I think he wants to run 110v out 150 feet, and then power his layout and pumps. Having 2 fountains with pumps, one of them a spa pump, and a spa that draws 60 amps at 220, I think I understand his current requirements.
The short answer is you need 8 gauge wire.
10 gauge is good for 30 amps, per national code.
http://answers.yahoo.com/question/index?qid=20091011161810AAsYWwd
Regards, Greg
Visit my site: http://www.elmassian.com - lots of tips on locos, rolling stock and more.
Click here for Greg's web site
Hi Why 40amps that hell of a lot of power, max for trains 10 amps you wont need more The power to the pumps needs to come off a differant supply and be covered by a circuit breaker NOT on the same power as for the trains. The pumps should tell you what cable to use. Train power look in any railway mag that will give you a choice of cable for your run When laying cables I would recomend feeding it though plastic conduit always use the bigest you can buy if you think at a later date you will want to put more cabeles in lay a second tube of conduit. Can I surjest in your bio you give a guide as to where you are this help us when replying to posts, and there maybe someone local to you that can help with advice and if you desided that they could drop by and offer help. As you can see I live in England. Hope this helps
Age is only a state of mind, keep the mind active and enjoy life
I am installing a garden railroad around two mountains and a koi pond. Right now I have extension cords run across the yard to power the pumps. I want to bury wires to supply the power for the pumps and the trains, but don't know what kind or size wire to use. I intend to run 40 amps over a length of about 150 feet. What gauge wire will be required to keep from losing too much power?
Get the Garden Railways newsletter delivered to your inbox twice a month