What causes fault code SAF-003 (Guard Door Interlock Open)?

Guard door actually open — close and latch securely. Interlock switch actuator misaligned with switch body. Interlock switch failed — contacts not closing when actuated. Door hinge sagging — actuator no longer reaching switch. Wiring fault between switch and safety relay/PLC

How do I fix fault code SAF-003?

Close and latch the guard door securely. Verify interlock switch actuation — watch LED indicator on switch body. Realign switch actuator if needed — adjust mounting bracket. Check door hinge — tighten or replace if sagging. Test switch with meter — continuity when actuator is engaged. Check wiring from switch to safety relay input. Replace switch if mechanical actuation is correct but no electrical output

Guard Door Interlock Open

SAF-003

Machine guard door interlock switch indicates door is open. Machine is locked out from automatic operation.

medium general packaging palletizer

safety guard door interlock switch lockout

Probable Causes (ranked)

Guard door actually open — close and latch securely
Interlock switch actuator misaligned with switch body
Interlock switch failed — contacts not closing when actuated
Door hinge sagging — actuator no longer reaching switch
Wiring fault between switch and safety relay/PLC

Fix Steps

1 Close and latch the guard door securely
2 Verify interlock switch actuation — watch LED indicator on switch body
3 Realign switch actuator if needed — adjust mounting bracket
4 Check door hinge — tighten or replace if sagging
5 Test switch with meter — continuity when actuator is engaged
6 Check wiring from switch to safety relay input
7 Replace switch if mechanical actuation is correct but no electrical output

Field Trick

If the switch LED comes ON when the door closes but the PLC doesn't see it, the problem is wiring between the switch and the PLC, not the switch itself.

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