Which sequence best aligns with properly addressing an interlock fault in an ALRE system?

• A. Reset interlocks first, then check wiring, and finally verify safety conditions.
• B. Check wiring, verify safety conditions, reset interlocks, and clear fault codes.
• C. Clear fault codes before inspecting wiring.
• D. Remove power and ignore the fault.

Answer: (B)

Addressing an interlock fault properly starts with confirming the fault’s cause through hardware checks and safety readiness. Begin by inspecting the wiring: look for loose connections, damaged insulation, corrosion, or any wiring faults that could set the interlock fault. The wiring path is a common source of interlock issues, so identifying and fixing any problems here prevents chasing symptoms instead of the real cause.

Next, verify all safety conditions are truly met. This means ensuring guards and safety devices are in place, sensors and switches indicate safe states, and power isolation or lockout procedures are correctly followed as required. Only when the system is confirmed to be in a safe state should you proceed to reset the interlocks. Resetting without this confirmation risks re-energizing or re-enabling equipment that may still be unsafe.

After the interlocks are reset, clear the fault codes so the diagnostic memory reflects a fresh start. This helps ensure future faults aren’t obscured by stale codes and that the system’s fault history accurately represents the current condition. Clearing codes before the root cause is resolved or before safety has been reassessed can hide ongoing issues and lead to repeat faults.

Removing power and ignoring the fault is not acceptable because it bypasses safety controls and can create dangerous conditions.