Panel Amp Calculations

How to Calculate Amperage Pull for a Single Phase Panel

Step #1:
Take the wattage of the heater and multiply it by the amount of total heaters and that gives you Total Watts

Example
4,000w @ 240v x (3) total heaters on panel = 12,000 Total Watts

Step #2:
Take the Total Watts and divide is by the Voltage of the Panel and that gives you Total Amps

Example
12,000/240 = 50 Total Amps

Step #3:
Take the Total Amps and multiply it by 1.25 and that gives you the Continuous Use Amps calculation

Example
50 x 1.25 = 62.5 Continuous Use Amps

Step #4:
Take the Continuous Use Amps and round it up to the nearest 5 and that gives you the Amp Feed Requirements from Panel of home to the Control box

Example
62.5 rounded to nearest 5 = 65 Amp Feed Requirements

How to Calculate Amperage Pull for a Three Phase Panel

Step #1:
Take the wattage of the heater and multiply it by the amount of total heaters and that gives you Total Watts

Example
4,000w @ 240v x (3) total heaters on panel = 12,000 Total Watts

Step #2:
Take the Total Watts and divide is by the Voltage of the Panel and that gives you Total Amps

Example
12,000/240 = 50 Total Amps

Step #3:
Take the Total Amps and divide it by 1.73 and that gives you the 3 Phase Amps

Example
50/1.73 = 28.90 3 Phase Amps

Step #4:
Take the 3 Phase Amps and multiply it by 1.25 and that gives you the Continuous Use Amps calculation

Example
28.90 x 1.25 = 36.12 Continuous Use Amps

Step #5:
Take the Continuous Use Amps and round it up to the nearest 5 and that gives you the Amp Feed Required from Panel of home to the Control box

Example
36.12 rounded to nearest 5 = 40 Amp Feed Required