In fail-safe operation, which statement about C-1 and C-2 latch valves and the normally open and normally closed solenoids is correct?

In fail-safe operation, which statement about C-1 and C-2 latch valves and the normally open and normally closed solenoids is correct?

• A. Technician A
• B. Technician B
• C. Both Technician A and Technician B
• D. Neither Technician A nor Technician B

Answer: (C)

Fail-safe operation means the system moves to a safe state when power is lost. The C-1 and C-2 latch valves use two solenoids—a normally open and a normally closed coil—so you can actively set or reset the valve, while the latch holds that position with minimal or no continuous power. When power is removed, springs and the default behavior of the NO/NC arrangement drive the valve to the safe position, ensuring the actuator or circuit goes to a safe state automatically. Because each technician described a valid aspect of how this dual-coil, latch valve arrangement provides both controllability and a safe default on power loss, both statements are correct.

Fail-safe operation means the system moves to a safe state when power is lost. The C-1 and C-2 latch valves use two solenoids—a normally open and a normally closed coil—so you can actively set or reset the valve, while the latch holds that position with minimal or no continuous power. When power is removed, springs and the default behavior of the NO/NC arrangement drive the valve to the safe position, ensuring the actuator or circuit goes to a safe state automatically. Because each technician described a valid aspect of how this dual-coil, latch valve arrangement provides both controllability and a safe default on power loss, both statements are correct.