HOLT Electricians Practice Exam

What is the correct order for motor calculations?

1. Overload protection, Motor full load current, Branch circuit protection

2. Motor full load current, Branch circuits conductor, Feeder conductors

3. Feeder protection, Overload protection, Branch circuits

4. Motor full load current, Overload protection, Branch circuit conductor

The correct answer is: Motor full load current, Overload protection, Branch circuit conductor

The correct order for motor calculations begins with determining the motor full load current, which is crucial as it provides the baseline electrical requirement of the motor under normal operating conditions. This calculation helps in selecting the appropriate size of the overload protection, ensuring that the motor can handle the current it draws during operation without being damaged. Overload protection is then established to protect the motor from drawing excessive current, which could lead to overheating and potential failure. Finally, the branch circuit conductor sizing is addressed. It needs to be adequately rated to handle the load associated with the motor while ensuring safe operation over extended periods. This order ensures that each step builds upon the previous one, allowing for proper and safe installation and operation of the motor within the electrical system. The focus on starting with the motor’s requirements and then addressing protection and conductor size reflects standard practices in electrical engineering, leading to effective and safe motor operation.