CALCULATION INFORMATION
SEPARATE HEATER ELECTRICAL SUPPLY:
Heater Amps times 1.25 is minimum circuit ampacity. Minimum circuit ampacity rounded up to the nearest standard protective device rating is maximum circuit protection.
COMBINED ELECTRICAL SUPPLY - COOLING ONLY UNITS:
Heater amps times 1.25 plus 6 is minimum circuit ampacity. Minimum circuit ampacity rounded up the nearest standard protective device rating is maximum circuit protection. COMPARE to Air Conditioners Labe (Write in the LARGER of the two ratings.
COMBINED ELECTRICAL SUPPLY - HEAT PUMPS:
Add heater amps to Heat Pump minimum circuit ampacity for a new total minimum ampacity. Minimum circuit ampacity rounded up to nearest standard protective device rating is maximum circuit protection.
STANDARD PROTECTIVE DEVICE RATINGS:
10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90 and 100 amps.
EXAMPLE:
Install a 47.1 amp heater in a heat pump and use combined single electric supply.
If Unit nameplate minimum circuit ampacity 35 - this makes the combined minimum ampacity (35 + 41.7) of 76.7 amps. 76.7 amps rounded up to nearest standard rating (80 amps). The combined maximum protective device is 80 A.