What is the circuit protection in amps used for each 5 kW of electric heat?

For electric heating systems, circuit protection is critical to prevent overheating and potential hazards. The National Electrical Code (NEC) provides guidelines for determining the appropriate circuit protection needed for electric heating loads.

When calculating circuit protection for electric heating, one must consider that the general guideline is to allow for a 125% factor of the load. For a 5 kW electric heater, the calculation goes as follows:

1. Determine the current draw of the heater. The formula to calculate the current in amps (I) for a resistive load like electric heat is:

I = Power (in watts) / Voltage (in volts)

Assuming a standard voltage of 240 volts, the calculation becomes:

I = 5000 watts / 240 volts ≈ 20.83 amps

2. To find the appropriate circuit breaker size, you must apply the 125% rule:

Circuit protection size = 20.83 amps × 1.25 ≈ 26 amps

Given this calculation, the typical circuit protection for electric heating systems for every 5 kW is rounded up to the next standard breaker size, which is usually a 30-amp circuit breaker. This accounts for additional safety and ensures that the circuit