Which timer is commonly used to keep lubricating pumps running after other motors have shut down?

Which timer is commonly used to keep lubricating pumps running after other motors have shut down?

• A. TOF Off-Delay timer
• B. TON On-Delay timer
• C. RTO Retentive timer
• D. Time-Driven Sequencing

Answer: (A)

The behavior being tested is using a timer that keeps an output on after its input has gone off. An off-delay timer holds the lubricating pump energized for a set period after the signal indicating that the other motors have shut down goes false. In practice, as long as the main motors are running the pump is on, and when they stop, the timer delays turning the pump off, giving it a final run time to ensure proper lubrication. This matches the requirement because the pump continues to run after the shutdown signal, rather than waiting to start or resetting immediately. A on-delay timer would delay turning the pump on rather than keep it running after shutdown, a retentive timer relates to preserving elapsed time across power cycles rather than a post-event hold, and time-driven sequencing describes a broader approach to event order rather than this specific post-event hold behavior.

The behavior being tested is using a timer that keeps an output on after its input has gone off. An off-delay timer holds the lubricating pump energized for a set period after the signal indicating that the other motors have shut down goes false. In practice, as long as the main motors are running the pump is on, and when they stop, the timer delays turning the pump off, giving it a final run time to ensure proper lubrication. This matches the requirement because the pump continues to run after the shutdown signal, rather than waiting to start or resetting immediately. A on-delay timer would delay turning the pump on rather than keep it running after shutdown, a retentive timer relates to preserving elapsed time across power cycles rather than a post-event hold, and time-driven sequencing describes a broader approach to event order rather than this specific post-event hold behavior.