Journeyman Electrician Practice Exam

For a small retail store of 1,600 square feet, how many 15-ampere, 120-volt general lighting branch circuits are required?

1. One

2. Two

3. Three

4. Four

The correct answer is: Two

To determine how many 15-ampere, 120-volt general lighting branch circuits are necessary for a retail store of 1,600 square feet, it's important to refer to the National Electrical Code (NEC) guidelines for general lighting load calculations. According to the NEC, a general lighting load is typically calculated based on a standard of 3 watts per square foot. For a retail space of 1,600 square feet, the total lighting load would be 1,600 square feet multiplied by 3 watts per square foot, resulting in a total lighting load of 4,800 watts. Given that each 15-ampere, 120-volt circuit can handle a maximum of 1,440 watts (calculated as 120 volts multiplied by 15 amperes), we need to calculate the total number of circuits by dividing the overall lighting load by the capacity of one circuit: 4,800 watts (total load) divided by 1,440 watts (capacity per circuit) equals approximately 3.33. Since the number of circuits must be a whole number, this rounds up to four circuits to adequately handle the lighting requirements. However, considering practical applications and potential local codes or additional requirements for the type of load