Replacing a 20-Amp Breaker with a 15-Amp Breaker: What You Need to Know

Whether due to safety concerns or as a simple upgrade, homeowners and electricians often find themselves in need of replacing a 20-amp breaker with a 15-amp breaker. This article will explore the considerations and implications of such a replacement, ensuring that you can make an informed decision.

Understanding Circuit Load

The first and most crucial consideration when switching from a 20-amp breaker to a 15-amp breaker is the circuit load. A 15-amp breaker will suffice only if the circuit is designed to handle up to 15 amps without overloading.

For example, if the circuit wiring is rated for 12-gauge wire, which is designed for 15-amp circuits, changing the breaker to 15-amp will provide adequate protection. However, it's important to ensure that the wiring and devices on the circuit are compatible with the 15-amp breaker.

Compliance with Local Electrical Codes

Always check local electrical codes and regulations before making any changes. In many jurisdictions, it is permissible to downsize a breaker for safety reasons, such as protecting a circuit that is currently overloading. However, the circuit should still be appropriate for the load it will carry.

For instance, if you notice that the 20-amp fuse has blown, it might indicate that the circuit is being overloaded. In such cases, it would be prudent to identify the cause of the overload and address it, rather than simply replacing the breaker.

Device Ratings and Safety Considerations

The devices connected to the circuit are another significant factor. If the devices are rated for 15 amps, then using a 15-amp breaker is appropriate. However, if there are devices that require a 20-amp circuit, keeping the original 20-amp breaker is essential.

A 15-amp breaker will trip if the current exceeds 15 amps, providing protection against overloads. However, if the circuit was previously protected by a 20-amp breaker, it's crucial that the load does not exceed the new breaker's capacity.

Professional consultation is recommended for circuits that are part of a larger system. A licensed electrician can provide valuable insights and ensure that all aspects of the circuit are safely upgraded or maintained.

Physical Installation and Safety

Physically replacing a breaker involves buying the correct brand and style, but using it properly is a different matter. The temperature rating and wire gauge are critical factors. Generally, 20-amp breakers supply 12 AWG 90 C wire in typical 120/240 VAC split-Edison panels.

It is possible to change a 20-amp breaker to a 15-amp breaker, but doing so in a circuit wired for 12 AWG requires verifying that the outlets are also rated for 15 amps. Otherwise, the risk of overheating and fire increases, especially if the wiring is 14 AWG.

A 20-amp outlet, for example, might look like this:

Conclusion

Replacing a 20-amp breaker with a 15-amp breaker involves several important considerations. Always prioritize safety, adhere to local codes, and consult a licensed electrician if necessary.