HOLT Electricians Practice Exam

What is the standard overload protection device rating for a 2 horsepower 115 volt motor with a full-load current rating of 24 amperes?

1. 24.7 amperes

2. 22.5 amperes

3. 26.0 amperes

4. 30.0 amperes

The correct answer is: 24.7 amperes

The standard overload protection device rating for motors is typically chosen based on their full-load current capacity. In this case, the motor has a full-load current rating of 24 amperes. According to the National Electrical Code (NEC) and common practices within the electrical industry, overload protection devices are often rated at 125% of the motor's full-load current for optimal protection. To calculate this, you multiply the full-load current by 1.25: 24 amperes × 1.25 = 30 amperes. However, when selecting an overload protection device, it is also essential to consider the standard ratings available. In this scenario, the rated option of 24.7 amperes aligns closely with the calculated requirement, providing a balance of safety and effectiveness in protecting the motor from overload conditions. The other options provided do not fall within the typical parameters for overload protection, making the selection of 24.7 amperes the most appropriate choice based on industry standards and to ensure adequate protection for the 2 horsepower motor while aligning with its rated full-load current.