How many amps does an air handler electric heat strip pull per 5kW bank during emergency operation?
Short answer
A single 5kW electric heat strip in an air handler draws 20.83 amps at standard 240-volt single-phase power during emergency operation. Because heating coils represent continuous electrical loads, standard electrical rules require a 125 percent safety multiplier, making a 30-amp double-pole circuit breaker and 10 AWG copper wire mandatory. If the indoor blower motor shares the circuit, add 2.0 to 4.5 full load amps.
A single 5kW electric heat strip bank in an air handler draws 20.83 amps at standard 240-volt single-phase power, requiring a dedicated 30-amp double-pole circuit breaker and 10 AWG copper wire.
When a heat pump outdoor unit drops below 30 degrees Fahrenheit or locks out, the system activates emergency heat mode, running purely on resistive auxiliary coils inside the indoor air handler. Calculating exact amperage ensures your electrical panel and branch wiring handle peak winter heating loads safely without nuisance trips.
If you only do one thing: Size circuit breakers and wiring using the standard 125 percent continuous load multiplier, which rates a 20.83-amp element at 26.04 amps minimum circuit ampacity.
- Resistive element draw: A 5,000-watt heating element draws 20.83 amps at 240 volts, 22.73 amps at 220 volts, and 24.04 amps when installed on commercial 208-volt power legs.
- Overcurrent protection: National Electrical Code standards treat heating coils as continuous loads, requiring circuit breakers rated for at least 125 percent of the element draw, making a 30-amp double-pole breaker standard for one 5kW bank.
- Conductor wire gauge: A single 5kW bank requires minimum 10 AWG (American Wire Gauge) copper conductors rated at 75°C to carry up to 30 amps safely over standard residential distances.
- Blower motor load: When an air handler's internal blower motor shares the primary power supply circuit with the first 5kW stage, add 2.0 to 4.5 full load amps to your total circuit calculation.
- Multi-bank configurations: Systems with 10kW draw 41.67 amps (requiring a 60-amp circuit) and 15kW packages draw 62.5 amps (requiring split 30-amp and 60-amp feeds or a single 90-amp supply).
- Watch out for: Voltage drops below 240V that reduce heating output from 17,060 BTUs per hour down to 12,800 BTUs per hour on 208V feeds while increasing current draw on motorized components.
- Watch out for: Undersized 100-amp to 150-amp main electrical service panels that trip main breakers when multi-stage heat strips engage simultaneously with water heaters and appliances.
- Watch out for: Normal dust burn-off smells lasting 15 to 30 minutes during first seasonal startup being mistaken for loose, overheating electrical terminal connections.
Check the equipment nameplate for the manufacturer's specified minimum circuit ampacity before servicing. For air handler diagnostics, wiring inspections, or emergency heating service, contact your local ARS/Rescue Rooter team at 866-399-2885.