The "Rule of Fourth"

(The "Rule of Fourth" can be used to substitute one heating element with other heating elements)

This solution may come in handy if you do not have heaters with the higher voltage available (for example 480V). 240V heaters are much more common than 480V heaters. So there is a bigger chance you may find them.

You can replace one 480 heater with 240 heaters and obtain the same wattage.


Divide the wattage by 4 and the voltage by 2 to find the equivalent wattage and voltage.

V

W

R

480

1000

230.4

240

250

230.4


Note: Always work from high voltage to low voltage when converting voltage/wattage. Increasing Wattage/Voltage could cause the heater to exceed its design criteria!