Can You Change a Circuit Breaker From 15 to 20 Amp?

Many homeowners do not understand the science behind the electrical circuit installation, resulting in unsafe changes made to the electrical system. It may seem like a simple, easy solution to install a 20-Amp breaker in the place of a 15-Amp breaker, especially if the breaker is continuously tripping, but is this a safe solution?

However, you can’t just switch out a smaller circuit breaker for a larger circuit breaker.

If your wiring is of the correct gauge, you can change a 15-Amp circuit breaker to a 20-Amp breaker. A 15-Amp circuit uses a 14-gauge wire. A 20-Amp circuit breaker uses a 12-gauge wire. If the copper wire is 12 AWG, you can replace the 15A breaker with a 20A breaker.

Homeowners who like to DIY problems in their homes may consider swapping a 20-Amp breaker for a 15-Amp breaker to be a solution to remedy various electrical issues, from adding 15-amp outlet to stopping a 15-Amp breaker from tripping continuously. Can you change a dedicated circuit breaker from a 15 to 20-Amp? Let’s discover the answer to this question and why it may not be a good idea.

Can You Change a 15-Amp Breaker to a 20-Amp Breaker?

Changing a 15-Amp breaker to a 20-Amp breaker is a reasonably simple task to complete, but it should only be changed to a 20-Amp if the AWG wire is the adequate gauge wire, i.e., a 12-gauge or 10-gauge wire, that can carry that level of current safely.

It only takes a few essential tools and the replacement breaker to get the job done. However, if the branch circuit is a 14-gauge wire, you’ll need to run a new 12-gauge wire first to safely install a 20-Amp breaker in the electrical panel and a 20-Amp outlet on the end of the circuit.

The tools you will need to do the job include the following.

  • Insulated gloves, preferably rubber, for additional safety
  • A flathead screwdriver
  • A non-contact voltage meter or a multimeter
  • 12 gauge wire
  • A headlamp for additional lighting

Complete the following steps to change the breaker from a 15-Amp to a 20-Amp.

1. Switch Off The Mains Supply

It is always safer to work with no current flowing through the circuit breaker panel. Switch off the main supply switch before opening the panel.

2. Open The Breaker Panel

Put on your insulating gloves and use the flat head screwdriver to remove the cover from the circuit breaker panel box. Hold the cover plate in place with one hand while you remove the last screw to prevent the cover plate from falling when the last screw is removed.

3. Make Sure The Wire Gauge Is Correct.

Examine the wire gauge on the circuit you want to replace the breaker. For a 14-gauge wire, sometimes referred to as #14 AWG, then you cannot place a 20-Amp circuit breaker in this circuit.

If you want to continue with the replacement, you will need to replace the branch circuit wiring with a 12-gauge wire. Fitting a 20-Amp circuit breaker to a 14-gauge wire will contravene the NEC and pose a severe safety risk for your home.

If you are unsure how to tell the difference between the two-wire gauges, the 14-gauge wire is 0.06-inches thick, while the 12-gauge wire is 0.08-inches thick. You can identify the gauge wires on the outer wire sheathing.

If you confirm you have the correct wire size, your new 20-Amp breaker can handle the circuit load.

4. Release The Old Circuit Breaker

Use your headlamp for extra lighting for this step, mainly if the breaker box panel is in a dark location. Use your multimeter of contactless volt-meter to ensure none of the wires carry any current.

Undo the screws holding the wires in place on the circuit breaker and push them to the side so they are out of the way. Depending on your circuit breaker type, unclip or unscrew it for the breaker box panel housing.

5. Fit The New Circuit Breaker

Clip or screw the new circuit breaker into place, and connect the wires to the new circuit breaker. Once the wires are connected, switch on the mains supply switch and switch on your new breaker.

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Use the multimeter to check the voltage across all the circuit breakers to ensure that your voltage across the new breaker matches the other breakers. This will indicate whether your new circuit breaker allows the correct voltage through it.

6. Close Up

Switch off the mains supply again and replace the breaker box cover plate. It is safer to do this with the power off to prevent a screwdriver from slipping and touching a hot wire.

Once the cover plate is back in place, switch on the main supply breaker and ensure all circuit breakers are switched on, including the newly replaced one.

Can You Upgrade A Circuit Breaker?

You can upgrade a circuit breaker to a new design circuit breaker as long as the new breaker will fit in the mountings in the breaker box and the breaker is rated for the same amperage as the original breaker.

You can upgrade your breaker to a higher amperage-rated breaker as long as the wiring in the circuit is of the correct gauge. A 12-gauge wire is required for a 20-amp circuit breaker.

Can I Install a 20-Amp Circuit Breaker on 14-Gauge Wire?

You can install a larger size circuit breaker on a circuit if the physical wiring is rated for the larger breaker. In many homes, the contractor who wired the house will use a lighter gauge wire for circuits that draw less current, such as the light circuits. The 14-gauge wire used for these circuits is easier to pull and is cheaper.

Other contractors will use 12-gauge wire throughout the house, even on the 15-Amp circuits. This variance in wiring gauges requires you to ensure the branch circuit wire has the correct gauge wire for the larger breaker. A 20-Amp circuit breaker needs a 12-gauge circuit wire to comply with the NEC and for safety.

Can You Put a 20-Amp Receptacle on a 15-Amp Circuit?

15-Amp and 20-Amp are separate circuits and use different AWG wire sizes. Using the correct amp wire size is crucial. Let’s examine why.

It is theoretically possible to put a 20-Amp outlet on a 15-Amp circuit because the 15-Amp circuit breakers will protect the circuit should the amp load be exceeded. Like an electric heater or power tools, certain appliances can cause an overloaded circuit that could trip the 15-Amp breaker.

However, putting a 20-Amp outlet on the circuit could cause overloading more frequently, depending on the devices you connect to the single outlet, which can cause the breaker to trip often.

According to NEC current codes Table 210.21(B)(3), installing a 20-Amp receptacle on a 15-Amp circuit is not permitted. Doing so will make your home’s electrical wiring non-compliant with the NEC codes.

This example shows that if a configuration works in theory, it may not necessarily be compliant with the code.

Conclusion

The regulations contained in the NEC are put in place to ensure safe practices are used when using electricity in the home. You should not make changes to the electrical system in your home that contravene any of these regulations since they are there to make the systems safer in the house.

Consequently, you should only replace a 15-Amp breaker with a 20-Amp breaker if the branch circuit has a 12-gauge wire that complies with the use of a 20-Amp circuit breaker.

References

Can I Replace a 15-Amp Breaker with a 20-Amp One?

How to Change a Circuit Breaker from 15 to 20 Amp?

Matching Wire Size to Circuit Amperage

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Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.

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