Electrical Question

[y0manda]

I'm going to install an outlet for a friend in his backyard and he is going to run a 15amp pump for his koi pond. My question is can I use 12AWG wire for the 130' run from the panel off an unused 20 amp circuit? Also he may use the new outdoor outlet for other things like a 300 watt low voltage lighting transformer. If you do recommend a 10 AWG wire what size circuit breaker should be used. Thanks.

[CarlD]

Whatever you do, be SURE the circuit is ground-faulted AT THE BREAKER BOX IN THE HOUSE! Do NOT rely on a GFI outlet--it needs a GFI breaker.

[matt4x4]

12 awg for 130 feet is fine.

[CliffTex]

Carl,

What has been your experience to recommend not using the GFI at the outlet? I thought that as long as the outlet was well protected from weather that it would be good enough. I have an electrician friend that said the breakers were a pain and the outlet type would be fine. Granted he climbs poles and deals with high voltage everyday but I trust his word. Please tell me your reasons as I sure don't want the kiddo's to fry by accident.

[MarkC]

I think the idea of the breaker is to protect the whole system from the main breaker panel all the way out to the outlet. If you just use a GFI outlet and have a problem in the wiring (digging accident or whatever) your GFI outlet won't sense that and the wire will still be hot.

[CarlD]

Let's be precise. By breaker we don't mean a regular circuit breaker, but instead a GFCI circuit breaker. Given that clarification MarkC's reasons are the same as mine. The WHOLE circuit is ground-faulted, not just the outlet.

But I'm not a bonded electrician, not even an electrician. Why does your friend call them a pain? Is it that they are a pain to install or that they are unreliable? If it's the former, well that's too darn bad--I've installed them myself and they usually take up 2 slots for one GFCI breaker, instead of one. If it's that latter, I'd like to hear about the problems.

But he/she is your friend. You have to choose who's advice you take, and why.

[CliffTex]

Mark & Carl,

I appreciate your answers. I didn't even think about the 125' run underground and the GFI not working the whole distance. We have already had our doofus Golden Retriever dig up the wire once and start chewing on it. If nothing else it could save the bonehead from being fried if he does it when no one is home to catch him.

Thanks again and as always the input from the board is AWESOME!

Cliff

[Poconos]

The copper wire resistance for 130' would be about .42 ohm (1.62 ohm per 1000') for 12 gauge. With a 10 amp load that would be about a 4.2 volt drop. For 10 gauge this drops to 1.02 ohm per 1000'. The 12 gauge run should normally not be a problem. As for the run itself, when you bury it consider burying a PVC pipe for a conduit and making it big enough to handle anything else you may want to fish at a later time. A lesson I've learned over the years is if you dig a trench to bury something once, chances are you'll dig again later for something else. Do it once. Pipe is cheap and it would give your dog another obstacle.
Al

[CliffTex]

Thanks Al!

I had thought of using PVC at 1st but that would require me to dig a "Real" trench. Being I live on 3" of topsoil with rock below I couldn't afford the type of ditch digger to cut a large trench. So using the high pressure nozzle on my power washer, I was able to cut a perfect trench for the gray 12ga romex. The other bonus for this method was there was little disruption and tearing up of the lawn. The only drawback was some shallow spots due to the rock.

Can't wait for summer!

Cliff

[tribe_fan]

You need to find out what the code is in you area - I cant imagine getting deep enough with a pressure washer to satisfy the "depth rule" of outdoor wire that is not in PVC. I think it is 12 -18 inches. (note: I hope you used outdooor rated wire !!)

With PCV you can go much less. I want to say 6 inches, but I'm not sure.

I also agree with the other posters - I think the whole outdoor run should be GFI protected. But a GFI outlet offers just as much protection (to devices "downstream" as a GFI breaker).