How To Install A Thirty Amp Line

Posted on: 13 May 2015

Certain high power appliances, such as dryers, require a power circuit that exceeds the normal fifteen or twenty amp lines for residential use. Installing a thirty amp line is slightly more difficult that adding an ordinary line, but the procedures are the same:

What you will need:

  • A thirty amp double breaker.

Because it handles twice the capacity of a regular fifteen amp breaker, a thirty amp breaker will require two breaker slots in your circuit box. Be sure to note the manufacturer of the circuit box, and purchase a breaker with the same brand name. Circuit breakers are not made to universally fit any circuit box.

  • A thirty amp outlet.

This outlet will be larger than a standard outlet, and will have unusual plug slots that are designed for a thirty amp plug.

  • Wall mounted gang box

If you intend to run the wiring inside finished walls and ceilings, which can be prohibitively difficult, you will not need a wall mounted box, but you may need an electrician who is skilled in dealing with running wire inside finished walls.

Running wire outside of finished walls may not be aesthetically appealing, but if your dryer and circuit box are located in utilitarian locations such as basements or laundry rooms, it shouldn't detract from the decor.

  • Wire

You will need at least ten gauge wire for a thirty amp line. Measure the distance from your breaker box to the intended location of your outlet. Remember, the wire will not run in a straight line form box to outlet, so allow for additional wire length.

  • Flexible conduit and connectors
  • ​You will run your wire through this protective covering, and connect it at circuit box and outlet. It is sold in various lengths, but remember not to buy the minimum length that you will need. Allow for twists and turns before you reach your connections. You should purchase conduit straps to secure the conduit if you intend to run it along ceilings or walls.
  • Wire stripper/cutter

You will need this tool to cut the wire to length, and to strip the insulation from the ends of the wires.

  • Hacksaw

You will need it to cut the conduit.

  • Flashlight

You will need to turn off the power when installing the circuit breaker.

Installing the line.

Begin by installing the conduit along walls and ceilings from the circuit box to the intended location of the outlet. Be sure that it is long enough to reach both locations without strain, allowing some slack for adjustments. When the conduit is in place, cut it with a hacksaw at the proper length, and add connectors to each end.

Begin to feed the wire through the conduit from the circuit box side. Ten gauge wire is thick, so it may take some time to maneuver it through the conduit. When it begin to protrude from the outlet side, remove two inches of insulation from one end of the three wires in the wire bundle, using the wire stripper tool. The blades will have numbered slots. Place the wire in the slots for ten gauge wire, close the handles, and pull the wire through the blades.

Pull the stripped wires through the top opening of the outlet box, and attach them to the outlet per the instructions that accompany the outlet. Connection types may vary, but be very sure to secure the wires adequately before proceeding. Ten gauge wire is very difficult to bend, and carries enough charge to melt the outlet or cause a fire if not properly secured.

When the wires are attached, screw the outlet to the outlet box, and the box to the wall. Connect the conduit to the box with the connector.

At the circuit box, cut the wire, allowing several inches of wire beyond the point of the circuit box entrance, and strip two inches of insulation from the ends of the wires.

Turn off the main breaker to the house. You will need your flashlight to punch out one of the scored holes in the side of your circuit box, and two parallel slots in the box. Push the stripped wires through the hole in the side, and attach the black and white wires to the thirty amp breaker ,and the green or copper colored wire to the grounding bar inside the circuit box. Snap the breaker into place ,and attach the conduit to the box with the connector.

Flip on the main breaker, and the job is complete. For more help, or if you have other questions, contact a company like Royal Plus Electric.