In a timer relay for ST, what relays must be de-energized?

In a timer relay for ST, what relays must be de-energized?

• A. TP energized
• B. TP de-energized and H de-energized
• C. H energized
• D. TP de-energized and TP energized advanced

Answer: (B)

The correct response involves understanding the operation of timer relays, particularly in the context of a specific control system referred to as ST. In a timer relay scenario, the state of the relays greatly influences the timing and the function of the control system. For the system to function correctly, it is critical that specific relays are de-energized at the appropriate time. The choice indicating that both TP (Timer Pulse) is de-energized and H (Hold) is de-energized is necessary because if either of these relays remains energized, it could interfere with the timer's ability to reset or operate as intended. Having TP de-energized ensures that the pulse condition is no longer maintained, allowing the timer relay to progress without conflict from an ongoing pulse. Similarly, ensuring that H is de-energized indicates that any holding state is also cleared, enabling a fresh cycle for the timer relay to operate effectively. In essence, the de-energizing of both TP and H is crucial for the timer relay to be in a stable state, permitting proper timing functions and preventing any unintended overlap of operations or states that could negatively impact the control scheme.

The correct response involves understanding the operation of timer relays, particularly in the context of a specific control system referred to as ST. In a timer relay scenario, the state of the relays greatly influences the timing and the function of the control system.

For the system to function correctly, it is critical that specific relays are de-energized at the appropriate time. The choice indicating that both TP (Timer Pulse) is de-energized and H (Hold) is de-energized is necessary because if either of these relays remains energized, it could interfere with the timer's ability to reset or operate as intended.

Having TP de-energized ensures that the pulse condition is no longer maintained, allowing the timer relay to progress without conflict from an ongoing pulse. Similarly, ensuring that H is de-energized indicates that any holding state is also cleared, enabling a fresh cycle for the timer relay to operate effectively.

In essence, the de-energizing of both TP and H is crucial for the timer relay to be in a stable state, permitting proper timing functions and preventing any unintended overlap of operations or states that could negatively impact the control scheme.