#100 amp service to barn. wire size code#

All the wires are heavy, 6-gauge to supply the required 60 amps. Here, because it’s a 240v circuit, two 120v conductors, one neutral, and a ground are tied to the rope and pulled through the conduit.

#100 amp service to barn. wire size code#

In conduit, code requires the use of individual conductors rather than sheathed cable (typical house wiring where two or three conductors plus a ground wire are wrapped together in an outer shell).

With the fish tape through the conduit, Scott ties ¼ inch rope to the fish tape’s end and pulls the rope back to the far end.

Here, it’s useful to have a helper, in this case the homeowner, to know when the fish tape arrives at the far end. The first step in getting the wires into the pipe is to run an electrician’s fish tape from one end to the other.With some grass seed, mulch straw, water, and time, the excavation will blend back into the lawn. With all the conduit installed, the trench is backfilled using the dirt that came out of it.In one spot where the trencher encountered ledge and couldn’t dig deep enough, a 2 inch thick layer of concrete is placed over the conduit, sand, and caution tape.On top of the sand, Scott lays red caution tape to alert anyone digging here in the future that there’s underground power. With all the conduit laid in the trench, it’s covered with a protective layer of sand.Once the conduit cools, the new shape is permanent. Where gentle bends are required, heat from a special propane torch is used to soften the plastic pipe enough to be bent.Special glue is used to secure the joints. Using 1 ½ inch PVC conduit will allow plenty of room for pulling wires.It’s important to have dug the trench deep enough so that even with his additional material, the conduit will be 18 inches or more deep. To protect the conduit from sharp rocks, a couple of inches of sand is placed in the trench.Even this machine can’t get through ledge, or bedrock, though, so another step will be required later on. Digging a trench deep enough (For 240v power, code requires the conduit to be at least 18 inches below the surface) goes much faster with a trenching machine.Not only is this service free, it’s legally required. This service sends out a technician who’ll locate and mark any existing underground utilities so they aren’t damaged by digging. Before doing an earthwork, Scott calls 811, the universal Call Before You Dig number. Moving outside, it’s time to dig the trench.Adding a subpanel next to the house’s main breaker simplifies the wiring connections.Find the house’s main panel and determine whether there’s enough power coming in meet the outbuilding’s needs, as well as if there’s enough space left to add the new circuit breaker.Will it need 240v power, or is 120v enough? What kind of electrical loads will there be? This determines the size of the feed wire, as well as the size of the new circuit breaker needed at the house’s main panel. Determine what the power needs of the outbuilding will be.In this video, This Old House’s electrician Scott Caron shows us how he does the job. Run black, red, white and green wires from the sub-panel box to the main panel box.From determining how many volts and amps that a shed needs, to knowing whether the existing electrical service can provide that, to digging a code-compliant trench for conduit, powering an outbuilding is probably a job for a pro.Run the wire from the main panel to the sub-panel box.Use #8 THHN wire for a 50-amp sub-panel or #2 THHN wire if the sub-panel is 100 amps.Some local codes require the backer to be painted black. Screw the sub panel box to the center of the backer and connect the conduit to the sub panel.Screw a piece of plywood that is 6 inches bigger than the sub panel to the wall where the sub panel will be mounted.If the concrete is already done, run the conduit up the wall on the outside of the garage and use a PVC LB access fitting to go through the wall where the sub panel box is to be mounted.Use a 90-degree sweep connector, instead of a sharp 90-degree connector, to make it easier to pull the wire through.If concrete has not been poured in the garage, run conduit down into the ground on the inside of the garage.Run the conduit from the garage to the main panel box.Use 1 1/4-inch PVC conduit for a 100-amp sub panel or 1-inch PVC conduit if the sub panel is 50 amps or less.