What is the minimum size breaker required for an electric furnace?

The minimum size breaker required for an electric furnace is determined by the current draw of the furnace and the National Electrical Code (NEC) guidelines. Electric furnaces typically require a breaker that can handle their electrical load safely without tripping during normal operation.

Most electric furnaces will have a specified amperage on the nameplate, and these usually suggest a breaker size that is at least 125% of the full load current. For example, if an electric furnace has a full load current of 24 amps, multiplying this by 1.25 gives 30 amps, which is why a 30-amp breaker is commonly required.

Choosing a breaker that is too small can lead to nuisance tripping, while one that is too large may not provide adequate protection against overloads, both of which can be a fire hazard. Therefore, a 30-amp breaker is generally the minimum required to ensure both safety and proper functioning of most electric furnaces, aligning with NEC regulations. This consideration makes 30 amps the optimal choice for this application.