Question

A single family residential has a computed load of 8 KVA and six branch circuits. Voltage is 240 volts, single-phase. The smallest sized allowed for the service entrance equipment is:

1. 60 amperes
2. 100 amperes
3. 150 amperes
4. 200 amperes

Answer 1

The smallest allowed size for the service entrance equipment is 60 amperes, as calculated based on the given load of 8 KVA at 240 volts single-phase power and standard service sizes.

Step-by-step explanation:

The smallest size allowed for the service entrance equipment for a single family residential with an 8 KVA load and 240 volts single-phase power can be calculated using the formula for electrical power: Power (P) = Voltage (V) × Current (I). Therefore, I = P / V. Plugging in the given values, we have I = 8000 VA / 240 V = 33.33 amperes. However, per electrical codes, the actual service size is recommended to be larger to handle potential peak loads and to adhere to safety guidelines that typically require a buffer. The standard service sizes available are 60, 100, 150, and 200 amperes. Since 33.33 amperes is less than the smallest standard size, we can select option 1, which is 60 amperes, as the smallest size allowed for the service entrance equipment.