A circuit supplying a continuous load must have a circuit breaker rated for what minimum amperage if it has a load of five kilowatts?

A circuit supplying a continuous load must have a circuit breaker rated for what minimum amperage if it has a load of five kilowatts?

• A. 50 A
• B. 60 A
• C. 70 A
• D. 80 A

Answer: (B)

To determine the minimum amperage rating for the circuit breaker in a circuit supplying a continuous load of five kilowatts, it's essential to perform a calculation based on the electrical power formula: Power (in watts) is equal to Voltage (in volts) multiplied by Current (in amperes). In this context, for residential circuits in the United States, the standard voltage is typically 120V or 240V. Assuming the circuit operates at 240V, the calculation would be as follows: 1. Convert kilowatts to watts: 5 kilowatts = 5000 watts. 2. Use the power formula rearranged to find current: Current (I) = Power (P) / Voltage (V). 3. So, for a 240V circuit: I = 5000 watts / 240 volts = approximately 20.83 amperes. However, since this is a continuous load, it's important to apply the National Electrical Code (NEC) requirement, which mandates that a circuit breaker must be rated at least 125% of the continuous load. Therefore, calculating 125% of 20.83 amperes gives: 20.83 amperes × 1.25 = approximately 26 amper

To determine the minimum amperage rating for the circuit breaker in a circuit supplying a continuous load of five kilowatts, it's essential to perform a calculation based on the electrical power formula:

Power (in watts) is equal to Voltage (in volts) multiplied by Current (in amperes). In this context, for residential circuits in the United States, the standard voltage is typically 120V or 240V.

Assuming the circuit operates at 240V, the calculation would be as follows:

1. Convert kilowatts to watts: 5 kilowatts = 5000 watts.

2. Use the power formula rearranged to find current: Current (I) = Power (P) / Voltage (V).

3. So, for a 240V circuit:

I = 5000 watts / 240 volts = approximately 20.83 amperes.

However, since this is a continuous load, it's important to apply the National Electrical Code (NEC) requirement, which mandates that a circuit breaker must be rated at least 125% of the continuous load. Therefore, calculating 125% of 20.83 amperes gives:

20.83 amperes × 1.25 = approximately 26 amper