What should be checked in Step 4 of the Safety Loop Defect procedure?

In Step 4 of the Safety Loop Defect procedure, verifying if the trip lower indicator light is off is crucial because it directly indicates the status of the safety circuit. The trip lower indicator light being off signifies that there are no faults detected in the safety loop, meaning the system is in a safe operating condition.

Ensuring that this light is off is part of a systematic approach to troubleshooting and guarantees that there are no underlying issues preventing the safety mechanisms from functioning correctly. A safety loop designed to control and monitor safety-critical functions must be confirmed to be clear of faults before proceeding further in troubleshooting or operation, as this would prevent potential safety hazards.

Other checks, while important under different circumstances, do not deliver the same level of direct insight into the safety loop's integrity. Focusing on the state of the trip lower indicator light ensures a core safety function is verified, which is essential for any further actions.