Electricians - Electrical Install Question

[redpoint5]

I am planning to install a 15A outdoor outlet 30 ft away from the garage.

Yesterday I finished boring under the concrete pathway and installed a PVC pipe to route the cable underneath.

My first question is, what is the minimum code depth for direct burying my 14 awg UF-B cable in Vancouver, WA. I see conflicting info on the web, and looking up the code from the state/county seems impossible.

This site says I only need to bury the cable 12" deep. Other sources say I need to bury 24", and even up to 30".

I'm planning to piggyback this outdoor circuit off of an interior outlet, directly opposite of the interior junction box. I haven't installed this interior outlet yet. Is it acceptable to piggyback outlets on a circuit that is currently only used for garage lighting? I think I will run a new breaker for this new run, since the extra distance isn't too far, but I'm just curious what my other options are. Should I instead put the 2 new outlets on the same circuit that currently handles the existing 3 garage electrical outlets?

I understand that the circuit will require a GFCI prior to exiting the structure, so I will make the new interior outlet be GFCI.

Finally, I would like to run a water line through the same PVC conduit that goes under the concrete pathway to install a sprinkler system. Does code allow for water and electric to run in the same conduit?

[Cobb]

Sounds like the making of a future episode of Homes on Homes.

More importantly, what will this be powering? It maybe best to put on its own circuit if this is for an EV charging vs just a couple hundred watt block heater or Christmas lights.

[redpoint5]

I meant to mention that the outlet was just going to be used for a 20 watt LED landscape light.

[redpoint5]

Here is a map of my plan.

[toc]

Originally Posted by redpoint5

, I would like to run a water line through the same PVC conduit that goes under the concrete pathway to install a sprinkler system. Does code allow for water and electric to run in the same conduit?

Water and electricity here would be an absolute no.

Bury 600mm in orange conduit for the full run of cable. Safety first.

[hamsterpower]

I agree that water should definately not share a conduit with electric ever!
The depth of the trench usually is due to the local frost line. 3+ feet here in MA, but I don't know in OR. There is cable availible that can be buried legally without conduit, but that too could conflict with local code. Keep the cable in conduit all the way down the wall and up to the outlet mounted to the tree at the end. It can be without conduit for the horizontal run if deep enough. You should add a foot of sand on top of the cable.
There should not be any problem adding this new recepticle to the existing two garage outlets. Those in the garage *should* already be GFI protected. If they are not, add your GFI to the first in the chain. Do not however put two GFI recepticles on the same circuit as they tend to cancel eachother out.

[redpoint5]

I don't understand the purpose of GFCI outlets. The circuit breaker is already protecting from excessive current, so why put a second circuit breaker in?

[Xist]

Originally Posted by redpoint5

I don't understand the purpose of GFCI outlets. The circuit breaker is already protecting from excessive current, so why put a second circuit breaker in?

Breakfast in bed is good. Breakfast in bath is better.

[redpoint5]

I Googled it.

Ground Fault Circuit Interupter device protects us from receiving electric shocks from faults in the electrical devices we use in our home. It works by comparing the input current on the hot side to the output current on the neutral side. If there's the slightest difference in current, on the order of a few milliamps, then there is current leaking out somewhere, possibly through somebody's body. To protect us in this situation, the device very quickly cuts off the power supply to the leaking device, within 20-30 milliseconds, greatly reducing any possible human tissue damage from errant current.

So it doesn't trip to protect against fires from excessive current use, but instead trips if electricity leakage occurs to protect against electrocution.

It seems excessive considering how wimpy our 120v AC is in the States.

[Fat Charlie]

Originally Posted by redpoint5

Here is a map of my plan.

How about plan B? Admittedly no sprinkler line, but less of a lot of other things.