How to Wire a Garbage Disposal With a Plug-in Cord

By
Timothy Thiele
Timothy Thiele

Timothy Thiele has an associate degree in electronics and is an IBEW Local #176 Union Electrician with over 30 years of experience in residential, commercial, and industrial wiring.

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Updated on 05/30/22
Reviewed by
Larry Campbell
Larry Campbell
Reviewed by Larry Campbell
Larry Campbell is an electrical contractor with 36 years of experience in residential and light commercial electrical wiring. He worked as an electronic technician and later as an engineer for the IBM Corp. He is also a member of The Spruce Home Improvement Review Board.
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Fact checked by
Emily Estep
Emily Estep
Fact checked by Emily Estep

Emily Estep is a plant biologist and journalist who has worked for a variety of online news and media outlets, writing about and editing topics including environmental science and houseplants.

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Under the sink.
snyferok / Getty Images
Project Overview
  • Working Time: 30 mins
  • Total Time: 30 mins
  • Skill Level: Beginner
  • Estimated Cost: $10 to $15

Garbage disposals (sometimes called food disposers) can be connected to the electrical power supply in one of two ways. They are sometimes hardwired directly into a dedicated circuit, or they can be wired with an appliance cord that plugs into a wall outlet that is usually located inside the sink base cabinet. 

When hardwired, the disposal is connected to a switch that is installed in an electrical box either in the sink base cabinet or on a wall near the sink. If the switch is near the sink, there's usually a second box, serving as a junction box, inside the cabinet. Any exposed wiring inside the cabinet should be protected by flexible metal conduit (BX cable, or "Greenfield"). Most jurisdictions also allow this direct wiring to be protected within non-metallic flexible conduit or tubing.

With the plug-in configuration, the disposal cord plugs into an outlet (receptacle) located inside the sink cabinet. The outlet is controlled by a wall switch, which is usually located on the wall near the sink. The outlet is often wired as a split receptacle so that only one half of the outlet is controlled by the switch; the other half is always powered and can be used for another appliance, such as a water filter or dishwasher. This outlet can also just be a single outlet, with room for only one plug, though there are other configurations, as well.

Cords are not sold with disposals and must be purchased separately. There are several kits available that contain all the parts required for installation, such as a grounded appliance power cord with plug, a cord clamp, and plastic wire connectors. Be sure to use a grounded cord with the appropriate voltage and amperage ratings for your garbage disposal. It's usually easier to connect the cord to the disposal before mounting the disposal under the sink, but you can also complete the wiring after the unit is mounted.

What You'll Need

Equipment / Tools

  • Phillips screwdriver
  • Wire strippers
  • Flat head screwdriver (if needed)

Materials

  • Appliance power cord with plug (grounded)
  • Cord clamp
  • Plastic wire connectors (wire nuts)

Instructions

  1. Remove the Wiring Compartment Cover

    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).

    A photo of an electrical cover plate being removed.
    The Spruce / Timothy Thiele

  2. Install a Cord Clamp

    Install a cord clamp into the hole near the wiring compartment. Insert the threaded end of the clamp into the hole and secure it on the inside of the unit's base plate with the clamp's nut.

    You will have to reach through the wiring compartment to thread and tighten the nut onto the clamp. It may be necessary to tap on the lugs of the mounting nut with a flat head screwdriver to tighten it down securely. 

    Tip

    Some disposals are made so the cord clamp screws directly into the unit, so this step may vary depending on your model.

    A photo of a Romex wire connector clamp.
    The Spruce / Timothy Thiele

  3. Strip the Cord Wires (as needed)

    Using a wire stripper, prepare the appliance cord wires for connection by stripping about 3/4 inch of insulation from the end of each of the three insulated wires. 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, requiring that you use different notches on the wire stripper.)

    Tip

    Many cords have stripped wires; if so, you can skip this step. Some cords also have a ground wire with a preinstalled ring connector; leave this intact.

  4. Install the Cord

    Feed the end of the cord that has the stripped wires through the clamp and into the wiring compartment. Secure the cord in the clamp by tightening the two screws on the clamp. Don't overtighten; the cord should be held securely but not compressed or deformed by the clamp.

  5. Connect the Wires

    Wrap the bare-copper end of the green (ground) wire of the cord clockwise around the ground screw on the disposal (or use the ring connector). 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, using a wire connector. Connect the black (hot) cord wire to the black (hot) wire of the disposal with a wire connector. Gently tug on each wire to make sure it is secure.

    Tip

    With some disposals, the hot wire lead may be red rather than black. If so, connect this red wire lead to the black wire in the appliance cord. Some cords also aren't colored, in which case, the lead with ridges on the outer edge is the neutral or white wire, the center wire is the ground wire, and the wire with no ridges is the hot wire.

  6. Reattach the Wiring Compartment Cover

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

    After the disposal is completely installed and the plumbing connections are made, plug the disposal cord into a switch-controlled, GFCI-protected receptacle. Test the operation of the disposal by flipping the wall switch while running water through the sink. 

    A photo of how to replace a cover plate of a garbage disposal.
    The Spruce / Timothy Thiele

When to Call a Professional

Even novice DIYers can easily do the work of connecting a plug-in appliance cord to a garbage disposal. Running the electrical circuit to power that garbage disposal is another matter. If you do not already have the necessary switch-controlled wall receptacle (outlet), adding this wiring is a job best done by a licensed electrician, since it involves running cable and making connections at the main service panel. Most codes require that the garbage disposal must be served by a dedicated circuit that powers no other outlets or appliances.