The size of the circuit breaker you need for a microwave depends on the electrical requirements of the microwave and the wiring of your electrical system. Most household microwave ovens in the United States typically require a 15 or 20-amp circuit breaker. Here are some guidelines to help you determine the appropriate circuit breaker size for your microwave:
Check the microwave's power rating: Look for the microwave's power consumption specifications on the manufacturer's label or in the user manual. It is usually expressed in watts (W) or amps (A).
Convert watts to amps: If the power rating is provided in watts, you can determine the amperage by dividing the wattage by the voltage of your electrical system. In the US, the standard voltage is 120 volts. So, to convert watts to amps, use the formula: Amps = Watts / Volts.
Allow for a safety margin: To prevent circuit overloads and ensure safe operation, it's a good idea to provide a safety margin. A 15-amp circuit can safely handle around 80% of its rated capacity, while a 20-amp circuit can handle around 100% of its rated capacity.
For example, if your microwave's power rating is 1200 watts, you would calculate the amperage like this:
Amps = 1200 watts / 120 volts = 10 amps
In this case, a 15-amp circuit breaker should be sufficient to safely power the microwave. However, it's always best to consult a qualified electrician to ensure that your electrical system is properly wired to handle the microwave's power requirements and to determine the appropriate circuit breaker size based on your specific situation. Additionally, local electrical codes and regulations may also impact the sizing of the circuit breaker, so it's essential to comply with those as well.