Which condition indicates that the trip has been activated?

The condition that indicates the trip has been activated is when the trip lower indicator light is off. In many systems, the trip lower indicator light serves as a visual cue to show the operational status of a system's trip mechanism. When this light is off, it often signifies that the system has gone into a safe state, meaning that a trip event has occurred, and the system is no longer active or operational.

Understanding the other conditions helps in recognizing why they do not indicate that a trip has been activated. For example, the state of the Deadman’s device does not directly correlate with the trip activation status; it is functionally related to operator presence or control rather than indicating the trip’s status. On the other hand, sufficient pressure in the Main Reservoir does not inherently mean that a trip has or has not occurred; it merely indicates that the system has enough pressure, but not its operational safety state. Finally, while an illuminated Emergency Stop light could suggest that the system has been stopped, it does not specifically confirm that a trip validation procedure has been triggered—the condition of the trip lower indicator light is crucial for determining that.