80-Amp Feeder and Lighting for a New Pole Barn in Battle Ground, WA

A pole building goes up fast and then sits dark until somebody runs power to it. This one in Battle Ground got a proper 80-amp feeder rather than a cord from the house, and Newman Electric handled the run, the disconnect, the grounding and the lighting.

Sizing the feeder to the building

Eighty amps is a deliberate number, landed on an 80-amp Homeline breaker at the house and protected again by 80-amp fuses in a 100-amp fused disconnect at the barn.

That combination is worth explaining, because it looks like belt and braces:

• The breaker at the house protects the feeder itself over its 70-foot run
• The fused disconnect at the barn gives a local means of disconnect, which a detached structure with its own distribution is required to have
• The disconnect is rated 100 amps and fused at 80, which is normal: you size the enclosure to the frame and the fuses to the load

Seventy feet of #2 URD carries that comfortably. Conductor size on a feeder is set by the load, the distance and the voltage drop you are prepared to accept, and getting it wrong shows up as lights that dim every time something starts.

Two ground rods, not one

The building got two ground rods, and that is not belt and braces.

A single rod is only accepted where its resistance to earth is measured and proven low enough. Since almost nobody measures it, the practical rule is two rods, spaced, bonded together. On a rural Battle Ground lot with dry summer soil, that is the right call regardless of what a meter would say in February.

The structure is bonded, and the equipment ground runs with the feeder. Both are required, and a detached building relying on rods alone for fault clearing is one of the more dangerous shortcuts in the trade.

Lighting a truss ceiling

Inside, LED runs went up between the exposed trusses, with a high bay in the bay where the height called for it.

Pole barns are awkward to light because the trusses are both the obstruction and the mounting. Running linear LED along the truss line rather than trying to work around it gives even light down the length of the building, and it puts the fixtures where they can be reached from a ladder rather than a lift.

The exterior got a coach light at the personnel door, which is a small thing that gets used every single time somebody goes out there after dark.

Doing it while the building is empty

Every part of this was easier because the barn was new and empty. The trench had no landscaping to cross, the walls had nothing on them, and the ceiling was clear.

The same feeder and outbuilding work two years from now, with a shop full of equipment and a finished yard, is a materially more expensive job. Our guide to powering a detached shop or barn covers what to decide before the slab goes in.

Putting up a pole building around Battle Ground, Yacolt or Amboy? Call 360-828-7143 or size the feeder with us before the trench closes.