What is the minimum ampacity required to supply a 12.0 kW electric furnace with a 1/3-HP motor at 240 volts?

To determine the minimum ampacity required to supply a 12.0 kW electric furnace with a 1/3-HP motor at 240 volts, it is essential to consider the power requirements for both the furnace and the motor.

The power of the electric furnace is straightforward. Since 12.0 kW equals 12,000 watts and the voltage supply is 240 volts, we can calculate the current using the formula:

[

I = \frac{P}{V}

]

Where:

• ( I ) is the current in amperes,

• ( P ) is the power in watts,

• ( V ) is the voltage in volts.

Calculating for the electric furnace:

[

I = \frac{12000 \text{ watts}}{240 \text{ volts}} = 50 \text{ amperes}

]

Next, we need to determine the power requirement for the 1/3-HP motor. One horsepower (HP) is equivalent to approximately 746 watts, so a 1/3-HP motor would require:

[

\text{Power for motor} = \frac{746 \text{ watts}}{3} \approx 248.67