We've added a patio to our backyard.

Currently we have 2 lights near our backdoor that are controlled by a switch inside.

We wanted to add an outlet (always on) near the patio, in addition to a pole light (controlled via switch) and some low voltage landscape lighting (also controlled via switch).

Existing setup right now looks like this(enter image description here

Here is how we wanted to have it setup:

enter image description here

I don't know a ton about electrical - but can I run one ground wire to all 3 outdoor items?

Am I correct in thinking I would need 3 'hot' wires ran to the patio area (one for outlet, one for light, one for landscape lights) - 1 'ground' (which could be used on each item) and 1 'neutral' that could also be daisy chained?

I guess my questions are as follows:

  1. Can you use one ground for multiple items
  2. Can you use one neutral for multiple items or do they each need their own?

Trying to figure out how many wires I need to run to the patio and how it all needs to be thrown together.

  • Where are you on this planet, and are you OK with everything being on the same circuit as the existing patio lights? Sep 9, 2017 at 18:36
  • Ground is nothing but a safety shield. All current returns on neutral. If you are familiar with low-voltage electronic design, this is quite different. You tie all grounds together, but neutrals stay with their partner hot always. Also, all cable or conduit has equal currents, i.e. If you count returning current as negative, all the wires' current totals out to zero, always. Sep 9, 2017 at 19:20
  • @ThreePhaseEel - In Illinois. I actually would love everything on the same circuit as existing patio lights.
    – Hanny
    Sep 9, 2017 at 20:42
  • Is this on a 15 or a 20A circuit? Sep 10, 2017 at 0:54
  • @ThreePhaseEel - it's on a 15A circuit
    – Hanny
    Sep 10, 2017 at 3:07

1 Answer 1


This is unfortunately not as simple as it looks

You'd think you'd be able to get by with a simple direct buried 14/4 cable, and you're almost right. However, 14/4 UF is a non-starter (nobody makes it). So, you'll have to lay some Schedule 80 PVC conduit in your trench instead and pull 14 AWG THWNs (3 hots, 1 neutral, 1 ground, just as you were thinking) through that. The trench should be about 24" deep to make sure you meet the 18" minimum bury depth requirements, and should have a warning tape atop the conduit so that the next bloke who digs there gets a reminder before they get bit.

You'll want to use fat conduit (say 3/4" or 1" with reducing fittings) to make the pull not totally unmanageable, and your box inside will need to have a conduit knockout to fit the conduit (many plastic boxes don't, so you'll have to be careful when picking the box out). It's probably best to run the conduit up the outside of the wall and then have a weatherproof nonmetallic LB body going straight into the back of the box, for that matter, instead of having conduit coming into the foundation and then up through the top plate.

At the other end, you'll run the conduit up to a weatherproof nonmetallic type X body and then run a nipple from the type X body to a nonmetallic FS box atop that for your receptacle, all mounted to some scrap 2x6 that is used as a bracket attached to a 4x4 post in the ground. The two side ports run from the X body to weatherproof nonmetallic L bodies (an LL on the left and a LR on the right) which then run to conduits going back down into the ground to the light fixtures -- these conduits have one hot, a neutral, and a ground in them, with the splices being made in the X body.

Also, use different colors (anything besides white, grey, or green) for each of the hots here so that you can keep them straight in the outdoor wiring -- one of them will be an unswitched hot for the receptacle, while the other two are switched hots for each set of lights. Last but not least, make sure there's a "while in use" hood on the receptacle box -- an "extra duty" type should be used, even, to provide the best ruggedness available.

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