Does A Garbage Disposal Need Its Own Circuit? (Explained!)

As you feed your waste into the garbage disposal after meals, you must bear in mind that it uses a large amount of electrical power as it does the dirty work of grinding the garbage and passing it through your drainage pipes.

I use a dedicated circuit of 15 amps for my garbage disposal. It runs on a 14-gauge non-metallic wire with 2 primary wires and a ground wire, and I will advise this for your safety.

Garbage Disposal Need Its Own Circuit

Can Garbage Disposal Share A Circuit?

The National Electrical Code generally allows you to share a circuit between your garbage disposal and any other appliance in your kitchen, especially your dishwasher.

Local authorities may differ on this, so you should always check with local code authorities first or consult a local electrician.

You should also look through your disposal manual for your manufacturer’s recommendation.

Can Garbage Disposal And Dishwasher Be On The Same Circuit?

Garbage disposal and dishwasher can be on the same circuit if your local code authorities permit it.

When sharing a garbage disposal circuit with your dishwasher, the circuit must be 20 amps on a 12-gauge wire with 2 insulated wires and a bare ground wire. But for your safety, the combined ampere rating of the garbage disposal and the dishwasher must not be more than 16 amps.

(The national electrical code recommends that the combined ampere rating of the two appliances must not be more than 80% of the circuit ampere rating)

Generally, garbage disposal requires a dedicated 15-amp circuit and a dishwasher requires a dedicated 10-amp circuit, giving a combined 25-amp minimum requirement.

So it is always advisable to run them on different circuits. But with special branches, proper connections, and circuit breakers, your electrician can make them run on the same circuit.

Linking both appliances on a circuit will save you time and energy, but might cause you more trouble if you intend to run the dishwasher and garbage disposal at the same time.

Besides the risky combined ampere rating, it is also not hygienic to run the two appliances simultaneously as the waste from the garbage disposal can find its way to the water in the dishwasher and contaminate your dishes.

So if you must run both appliances at the same time, you must ensure your plumbing system supports it as well.

You will also need to be extra careful as this shared circuit connection poses a higher risk of malfunction and is more prone to electric sparks, fire outbreaks, etc.

Can A Refrigerator And Garbage Disposal Be On The Same Circuit?

If you are using an old traditional or a kitchen residential refrigerator, then you may connect it to the same circuit as your garbage disposal, provided the total ampere capacity is not more than 80% of the circuit ampere capacity.

But if you must install a modern refrigerator or plan to remodel your kitchen, you will be required to place your refrigerator on a different circuit of its own – a dedicated circuit of 20 amps.

When you are setting up this circuit, you should ensure that circuit breaker with AFCI devices are installed.

AFCI (Arc-Fault Circuit Interrupters) devices are recently recommended by the national electrical code. They can detect electrical sparks and faulty connections in circuits, break the circuit and prevent fire outbreaks.

If your refrigerator is located in the garage, basement, or within 6ft of a sink, then you will also need to install a GFCI device in your circuit.

GFCI (Ground-Fault Circuit Interruption) devices help to prevent electric shocks.

Can Microwave And Garbage Disposal Be On The Same Circuit?

As with refrigerators, old or countertop microwaves can share a circuit with other appliances such as garbage disposal as long as recommended ampere rating is not exceeded.

But modern microwaves often consume more power than older versions and are classified as part of “fixed equipment” – including modern refrigerators.

Most fixed-equipment has rotating large motors and generates a lot of heat.

According to the national electrical code requirements, fixed appliances must have their own dedicated circuits. So if you use a modern microwave, you should consider getting a dedicated circuit for it.

As with refrigerators, AFCI protection is required in this circuit, and this is a general requirement for appliances that are plugged into an outlet. Depending on your local code authorities, you might also need GFCI protection in this circuit.

Microwaves use standby power. So be sure to unplug your microwave when not in use if you don’t want to increase your monthly electricity bill.

Does Garbage Disposal Require A Switch?

Most garbage disposals require a switch, except you use a Batch Feed Garbage Disposal

Continuous Feed Garbage Disposals require a switch for start-and-stop control. They can work continuously and require a continuous supply of water, as the name implies.

Traditional garbage disposal switches are found on the walls but leave users prone to electric shock as they are mostly operated with wet hands.

Modern garbage disposals use any of the three kinds of switches below:

  • Air Switch
  • Wireless Switch
  • Toe-kick or Foot Switch

Batch Feed Garbage Disposals do not require a switch. They process garbage in batches, use a limited amount of water, and will start work as soon as you push down the cover.

Some of the differences between batch feed and continuous feed garbage disposal include:

  1. Batch Feed is safer and easier to use
  2. Batch Feed is easier to repair
  3. Batch Feed uses less water
  4. Batch Feed uses less power
  5. Batch Feed is less noisy and can be used almost quietly
  6. The installation process is simple and easy for Batch Feed
  7. Continuous Feed is faster in operation
  8. Continuous Feed is cheaper
  9. Continuous Feed occupies less space on the floor of your kitchen

Do Garbage Disposal Need To Be Grounded?

Grounding is not a mandatory requirement in the national electrical code.

Grounding serves as an alternative pathway for conducting electricity to the ground below your home. It comes in handy during a short circuit, power surge, electrical overloads, or other potentially dangerous situations.

Your garbage disposal may be connected to electricity directly through a circuit like mine or it might have an appliance plug connected to a wall outlet.

So since water is constantly circulating through them, you are at a high risk of electric shock – which can best be prevented by grounding.

You can confirm from your electrician and your user manual if there is a green wire in the connection. This wire is the grounded/earthed wire.

(The wire can also be green with yellow stripes)