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How to Wire an RV Air Conditioner

by William Collins

Whether you are rewiring an old air conditioner for your RV or installing a brand new unit, there are a few things to consider. An RV is not electrically the same as a house; when wiring an air conditioner, keep this in mind. In an RV, always wire the common and ground circuits separate and provide an isolated common circuit. If wired in the same manner as a house and there is a short circuit in any appliance, it is possible that the next person that touches the RV, while standing outside, will receive a severe shock.

Step 1

Locate the place on the roof of the RV to mount the new air conditioner and cut a 14 by 14 inch hole. Install per manufacturer instructions.

Step 2

Locate the alternating current circuit breaker box.

Step 3

Run Romex wire from the breaker box to the air conditioner. Run the wire through hidden places such as cabinets, closets, baseboards and ceiling.

Step 4

Attach the Romex cable securely to the walls with neoprene insulated cable clamps and Phillips screws. The cable must not be left hanging loose anywhere because the constant vibration of the road may cause breaks or shorts in time.

Step 5

Attach the air conditioner end of the Romex cable to the air conditioner junction box with a Romex clamp and strip off six inches of the outer jacket with the Romex cable ripper. Strip off 1/2 inch of insulation from end of the wires with the wire stripper.

Step 6

Connect the three wires inside the Romex cable to the three wires of the air conditioner with closed end connectors and wire crimpers. Match the alike colors and connect the wires, white to white, black to black and ground to ground.

Step 7

Turn off all alternating current power from your RV. Unplug it from shore power and make sure the inverter and generator are disconnected.

Step 8

Remove the circuit breaker cover. Break off a circuit breaker and cable knock-off from the RV breaker panel.

Step 9

Thread the Romex cable through a Romex clamp and install in the circuit breaker box.

Step 10

Strip off the outer jacket of the Romex cable with the cable ripper to expose the wires. Strip off 1/2 inch of insulation from the end of the wires with the wire stripper.

Step 11

Install a 15 amp circuit breaker in the RV breaker box for the air conditioner circuit.

Step 12

Connect the ground wire to the ground bus strip.

Step 13

Connect the white wire to the common bus strip. Make sure the green bonding screw is not screwed into this bus strip, if it is, remove it. The only place where the common and ground circuits should connect in an RV is at the shore power source, not in your RV.

Step 14

Connect the black wire to the 15 amp circuit breaker.

Replace the circuit breaker box cover, plug in to shore power, flip the new circuit breaker on and turn on your new air conditioner.

Tip

  • Minimize the chances of getting an electric shock by checking other electric appliances for proper common circuit isolation.

Warning

  • Keep the common circuit of your RV isolated from the ground circuit. Turn off all sources of alternating current before starting on this project.

Items you will need

  • 15 amp circuit breaker
  • Romex nonmetallic (NM) 10-2 copper cable
  • Neoprene insulated cable clamps
  • Phillips screws
  • Romex connector clamps
  • Closed end connectors
  • Romex cable ripper
  • Wire stripper
  • Wire crimper

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