Step 3 of 12 · Ch 1
3. Safety rules that never bend
Stop conditions, dry vs live testing, and the one-change rule.
Never touch THC arc-voltage terminals while energized. Raw plasma arc voltage can cause severe injury or death. Only a qualified person should connect arc-voltage wiring.
Never bypass the emergency stop, limit circuit, charge pump, enclosure interlock, or protective earth to keep production running.
Record the starting condition, make one controlled change, and test again. Restore the original setting if the change did not help.
Use a dry test whenever a live arc is not required — plasma power off or torch-firing output safely disabled.
Press the physical emergency stop, isolate plasma input power, and do not continue until the output path is proven safe.
1. Premier troubleshooting method
Make safe → reproduce → identify subsystem → one test → record → change one item.
2. Check order (keeps you and the machine safe)
1 Cold mechanical (power off) → 2 Dry motion (power on, torch OFF) → 3 Torch signal → 4 Live cut. Jumping ahead causes most support pain.
3. Stop immediately if
Motion is uncontrolled, an axis hits a hard stop, smoke/odor appears, conductors are hot, or the torch fires unexpectedly.
Warning: Unexpected fire: physical E-stop, isolate plasma input power, prove the output path before continuing.