50-Amp Sub Panel Run Out to a Backyard Shed in Vancouver, WA

Running power to a shed in a finished backyard isn’t like running it across an empty rural lot. There’s a patio, a lawn, flower beds, and a homeowner who’ll notice every one of them later. On this one in Vancouver, we ran a 50-amp feeder out to the shed and put the yard back.

Why 50 amps

Our Woodland job ran a 100-amp panel out to a shed. This one’s 50, and the difference isn’t budget. It’s sizing it for what the shed will really use.

The feeder size follows the load. Going bigger than you need costs you: bigger wire, a bigger trench, and less capacity left for the house. Fifty amps is a lot for a shed. It’ll run lights, outlets, a compressor and a heater without a problem.

When you’re planning a subpanel for an outbuilding, the question is what’s going in the building, not what sounds like plenty.

Grounding and bonding a detached building

This is what separates a safe shed feed from a dangerous one, and it’s what old DIY runs most often get wrong.

A shed with its own panel isn’t just an extension of the house panel:

1. Neutral and ground stay separate at the subpanel. They’re tied together once, at the main service, and nowhere else. Leaving the bonding screw in a subpanel is the classic mistake.
2. The shed needs its own ground rod. The ground wire from the house doesn’t replace it.
3. The ground wire still has to run with the feeder. A ground rod at the shed on its own won’t trip a breaker in a fault.

Get that wrong and the metal on everything in the shed can be at a different voltage from the ground you’re standing on.

New conduit instead of the old pipe

We ran new conduit instead of pulling wire through what was already in the ground.

Reusing old buried pipe is tempting and usually a bad bet. You don’t know what shape it’s in, whether it’s full of water, whether it was ever big enough for what you’re pulling, or whether it was even rated to be buried. Pull new wire into pipe you can’t inspect and you find out at the worst time.

Putting the yard back

The trench crossed the edge of a paver patio and a lawn, and we put the dirt on tarps instead of on the grass.

That’s what makes it possible to put the yard back. Dirt dumped right on the lawn kills the grass and mixes into it, and raking won’t fix it. Our guide to running power to a detached building covers the planning, and on a finished yard, the yard work is half the job.

Shed, shop or studio at the back of a finished Vancouver yard? Call 360-828-7143 or quote the shed feeder, and we’ll tell you what the trench involves.