1. Calculate the Current:
* Power (kW) = Voltage (V) x Current (A) x Power Factor (PF)
* We'll assume a power factor of 1 (typical for resistive heaters)
* 13.8 kW = 208 V x Current (A) x 1
* Current (A) = 13.8 kW / (208 V x 1) = 66.35 A
2. Choose the Breaker Size:
* Always round up to the next standard breaker size.
* In this case, the next standard breaker size is 70 amps.
Important Notes:
* National Electrical Code (NEC) Requirements: Consult the NEC for specific wiring and breaker requirements related to electric heaters. There may be additional considerations based on the heater's installation type and location.
* Wire Sizing: The wire size for the heater must also be compatible with the breaker size to prevent overheating and potential fire hazards. A qualified electrician should determine the appropriate wire gauge.
* Continuous Load: Electric heaters are considered continuous loads. The NEC requires derating the breaker for continuous loads. This means the breaker must have a rating of 125% of the calculated current. In this case, 125% of 66.35 A is approximately 83 A. However, a 70A breaker is acceptable as it is the closest standard size that is greater than 83A.
Always consult with a qualified electrician for specific electrical installations. They can ensure your system meets all safety codes and your individual needs.
