How to Connect a Garbage Disposal

A photo of an electrical cover plate being removed.
Remove Electrical Cover Plate. Timothy Thiele
  • 01 of 07

    Garbage Disposal Wiring Basics

    Garbage disposals, or disposers, can be connected with a cord and plug or they can be hard-wired with circuit wiring connecting directly to the disposal. When connected with a cord, the cord plugs into a switched-controlled receptacle (electrical outlet) that is typically installed in the sink-base cabinet. When hard-wired, the circuit wiring connected to the disposal runs to a switch that is installed in an electrical box either in the base cabinet or on a wall near the sink. The wiring between the disposer and switch typically is installed inside flexible metal conduit ("Greenfield") to protect the exposed portion of the circuit. 

    The following steps show you how to install an appliance cord to a garbage disposal. Cords typically are not sold with disposals and must be purchased separately. Be sure to use a grounded cord with the appropriate voltage and amperage ratings for your garage disposal. It's usually easier to connect the cord to the disposal before mounting the disposal under the sink, but you can complete the wiring after the unit is mounted, if desired. 

    Supplies Needed:

    • Phillips screwdriver
    • Appliance power cord with plug (grounded)
    • Cable clamp
    • Wire strippers
    • Plastic wire connectors (wire nuts)
    Continue to 2 of 7 below.
  • 02 of 07

    Wiring a Garbage Disposal: Step 1

    A photo of an electrical cover plate being removed.
    Remove Electrical Cover Plate. Timothy Thiele

    Remove the metal cover from the wiring compartment on the bottom of the garbage disposal unit. On most units, the cover is secured with a single screw. Remove the screw with a screwdriver and set the pieces aside (you will need them later). 

    Continue to 3 of 7 below.
  • 03 of 07

    Wiring a Garbage Disposal: Step 2

    A photo of a Romex wire connector clamp.
    Romex Wire Connector Clamp. Timothy Thiele

    Install a cable clamp into the hole near the wiring compartment. Insert the treaded end of clamp into the hole and secure it on the inside of the unit's base plate with the clamp's nut. You have to reach through the wiring compartment to install and tighten the nut. 

    Continue to 4 of 7 below.
  • 04 of 07

    Wiring a Garbage Disposal: Step 3

    A photo of stripped wires ready for connection in a garbage disposal.
    Stripped Wires in a Garbage Disposal Installation. Timothy Thiele

    Prepare the cord wires for connection by stripping about 3/4 inch of insulation from the ends of each of the three cord wires, using a wire stripper. If the cord wiring is stranded copper, be sure to use the "stranded" notches on the wire stripper. If the wiring is solid copper, use the "solid" notches. Stranded copper is slightly larger than solid copper of the same nominal size. 

    Continue to 5 of 7 below.
  • 05 of 07

    Wiring a Garbage Disposal: Step 4

    A photo of an electrical connection for a garbage disposal.
    Garbage Disposal Wiring. Timothy Thiele

    Feed the end of the cord (with the stripped wires) through the cable clamp and into the wiring compartment. Secure the cord in the clamp by tightening the two screws on the clamp. The cord should be held securely but not compressed or deformed by the clamp. 

    Continue to 6 of 7 below.
  • 06 of 07

    Wiring a Garbage Disposal: Step 5

     Wrap the bare-copper end of the green (ground) wire of the cord clockwise around the ground screw on the disposal. Tighten the ground screw with a screwdriver to secure the wire. Connect the white (neutral) cord wire to the white (neutral) wire on the disposal by twisting the bare-copper wire ends together and securing the connection with a wire connector. Twist the connector tightly, then gently tug on each of the white wires to make sure it is secure. Use the same technique to connect the black (hot) cord wire and the black (hot) wire of the disposal. 

    Continue to 7 of 7 below.
  • 07 of 07

    Wiring a Garbage Disposal: Step 6

    A photo of how to replace a cover plate of a garbage disposal.
    Electrical Cover Plate. Timothy Thiele

    Carefully tuck the wires into the wiring compartment. Reinstall the compartment cover, securing it with its screw. 

    Note: After the disposal is completely installed and the plumbing connections are made, plug in the disposal cord to a switch-controlled, GFCI-protected receptacle. GFCI protection is required by the National Electrical Code because the receptacle is located within 6 feet of the kitchen sink (in most cases).