NEIEP Mechanics Practice Exam

What will be the condition of the latching or PL relays when the car is at the top floor?

1. All set

2. Inactive

3. Unresponsive

4. Triggered

The correct answer is: All set

When considering the condition of latching or PL relays in the context of a lift or elevator system at the top floor, it's important to recognize the function these relays serve. Latching relays are designed to maintain their position after being activated. When the elevator reaches the top floor, the system's operational logic typically ensures that the elevator is safely held in place and that all pertinent conditions for continued operation are met. In this scenario, being at the top floor indicates that the elevator has completed its ascent and the necessary signals have been sent to the relays to keep them in a set state. This is crucial for preventing unintentional movement when the car is at the top and ensuring the safety of passengers. Therefore, when the elevator is at the top floor, the condition of the latching relays would indeed be that they are all set, indicating that the elevator is securely positioned, and the system is holding that state until an appropriate command is given to change it. The other options do not accurately reflect the condition of the relays at this stage. For instance, "inactive" suggests that the relays are not engaged at all, which is not the case since their state must indicate that the elevator is at a stop. Similarly,