The electrical furnace is a very high power appliance 8 10kw at the minimum and it should be on a 3 wire 120 240 volts single phase service which has two live wires to increase its current capacity.
Electric furnace breaker size.
So the double pole breaker is designed to trip and disconnect both live wires in the event of over current on either one of them.
If you live in a 1 500 square foot home and your btu per square foot needs are 45 your calculation will be 45 x 1 500 67 500 btu output.
Circuit breaker size and amps charts.
I used the 20 amp feeder to feed the electronic air cleaner only and used the 60 amp feeder to feed the furnace including the motor control and 5 kw resistance grid.
X 35 heating factor from the chart above 52 500 btu s required to heat your home.
By multiplying the volts by amps you will receive total wattage.
The maximum safe current limit is 80 of the rated size of breaker except some motors.
The thing that bothers me is that usually having two 60 amp breakers is indicative of a two circuit 20 kw furnace but i think what you have is a two circuit 25 kw furnace.
The input voltage will make a big difference in what size breaker you need to use.
Then to determine the heating output on a given electric furnace simply view the heating element btu options that most closely match your requirement.
Below is the given chart showing the of max current rating of breaker size for different types of load currents.
We are installing a goodman electrical furnace model aruf 14 or arpt 14 which has three heat elements that are supplied by a 60 amp and a 30 amp breakers.
The replacement unit installed takes a single feeder and only has 5 kw of resistance heat.
The exact amps an electric furnace requires is solely based on the size of the furnace and its performance capabilities.
Keep in mind that the breaker size should not increase the max amperage rating of cable and wire.
It has l1 and l2 on the 60 amp and l3 and l4 on the 30 amp.
A 25 kw furnace could be either a two or three cicuit unit.
The size of a breaker is determined by the amp draw.
I replaced the 60 amp breaker with a 40 amp breaker.
Multiply the btu number you ve selected by the square footage of your home to calculate the btu output of the furnace you need.
Used when figuring electrical material needs and is already calculated in the chart.