HOLT Electricians Practice Exam

Motor feeder conductors must be protected against short-circuits and ground faults, but not against which of the following?

1. Overloads

2. Short-circuits

3. Ground faults

4. All of the above

The correct answer is: Overloads

Motor feeder conductors are required to be protected against short-circuits and ground faults to ensure the safety and reliability of electrical systems. However, they are not necessarily required to be protected against overloads. This is because overload protection is primarily the responsibility of the motor's built-in thermal overload relay or other protective device specifically designed for that purpose. Overloads occur when the motor draws more current than rated for an extended period. While protecting motor feeders from overloads is crucial for the motor's longevity and preventing potential damage, the code does not mandate feeder conductors be equipped with their own separate overload protection. Instead, the focus is on ensuring that the conductors are adequately protected against conditions that could lead to immediate or catastrophic failures, like short-circuits and ground faults. In summary, while ensuring the safety of motor feeder conductors is of utmost importance, the specific protection against overloads is handled differently and is not a requirement for the conductors themselves. This allows for streamlined designs and reduces unnecessary complexity in the system.