6.5 Breakdown Response Standard (safe isolation, restart verification)

A machine breakdown is a high-pressure event where adrenaline often overrides protocol. This is when accidents happen. The pressure to "get back online" induces shortcuts—bypassing guards, skipping LOTO, or ignoring initial quality checks. This standard enforces a rigid sequence of operations: Secure the scene, Repair the root cause, and Validate the process before returning to production.

Safe Isolation (LOTO) Protocol

Never trust a software interlock to save your life. Software can crash; a padlock does not.

• If technician enters a danger zone (moving parts/high voltage) -> Then Apply Physical LOTO.
  • Constraint: The technician performing the work holds the only key.
• If machine requires power for diagnostics ("Hot Work") -> Then Establish a Controlled Perimeter.
  • Action: Use red/white barrier tape to exclude non-essential personnel.
  • Requirement: Two-person rule applies. The second person stands at the E-Stop.

Pro-Tip: "Test Before Touch." After applying the lock, attempt to start the machine. If it starts, your isolation point is wrong. This simple "Try" step has saved more fingers than any safety manual.

Breakdown Diagnosis & Repair

Do not just swap parts until the error clears. Understand the failure mode.

• If Component Failed -> Then Inspect the Upstream Cause.
  • Example: If a motor burned out, check the mechanical load (jammed belt) before installing the new motor. Otherwise, you will burn the new motor too.
• If Firmware/Parameter change is required -> Then Log the change in the Machine Passport.
  • Risk: Unlogged parameter tweaks create "ghost" defects that are impossible to trace later.

Restart Verification (The "Handshake")

The repair is not complete when the technician says "It's fixed." It is complete when Quality says "It's good."

• Step 1: Guarding Check
  • Action: Verify all safety covers are bolted down and interlocks are active.
  • Test: Open the guard while the machine is idling. If it does not alarm, Do Not Run.
• Step 2: Dry Run
  • Action: Run 5 cycles without product. Listen for abnormal noise or vibration.
• Step 3: Quality Validation (First Article)
  • Mandate: Produce 3 Verification Units.
  • Inspect: 100% inspection (AOI + X-Ray).
  • Sign-off: Quality Engineer must physically sign the "Return to Service" tag.

Final Checklist

Parameter	Metric / Rule	Critical State
Isolation	LOTO Status	Lock Applied + Verified
Hot Work	Safety Team	2-Person Rule
Root Cause	Diagnosis	Upstream Factor Checked
Guarding	Interlock Test	Functional Alarm
Restart Quality	First Article	3 Units @ 100% Inspection
Sign-Off	Authority	Quality Engineer