What causes fault code CONV-GUARD1 (Conveyor Guard Door Interlock Open)?

Guard door physically open — operator accessing the conveyor for maintenance or jam clearing. Guard door closed but interlock switch not actuating — switch misaligned with actuator. Interlock switch failed — contact stuck open or spring broken. Interlock switch wiring disconnected — wire broken at terminal or in conduit. Guard door hinge sagging — door is closed but doesn't align with switch actuator anymore

How do I fix fault code CONV-GUARD1?

Walk the conveyor section and visually check all guard doors — find the one that is open. If door is closed, check the interlock switch LED indicator — verify it shows actuated state. Manually press the interlock switch actuator — does the PLC input change state?. Check door alignment — close the door and verify the switch actuator key enters the switch head fully. Adjust hinge or strike plate if door has sagged and switch is not engaging. After closing guard door, press the safety reset button — most systems require deliberate reset

Conveyor Guard Door Interlock Open

CONV-GUARD1

A guard door interlock switch on the conveyor section is open. Conveyor section is stopped due to safety interlock. Guard must be closed and reset before conveyor will restart.

medium conveyor packaging palletizer

conveyor guard door interlock safety switch reset

Probable Causes (ranked)

Guard door physically open — operator accessing the conveyor for maintenance or jam clearing
Guard door closed but interlock switch not actuating — switch misaligned with actuator
Interlock switch failed — contact stuck open or spring broken
Interlock switch wiring disconnected — wire broken at terminal or in conduit
Guard door hinge sagging — door is closed but doesn't align with switch actuator anymore

Fix Steps

1 Walk the conveyor section and visually check all guard doors — find the one that is open
2 If door is closed, check the interlock switch LED indicator — verify it shows actuated state
3 Manually press the interlock switch actuator — does the PLC input change state?
4 Check door alignment — close the door and verify the switch actuator key enters the switch head fully
5 Adjust hinge or strike plate if door has sagged and switch is not engaging
6 After closing guard door, press the safety reset button — most systems require deliberate reset

Field Trick

When operators say 'all the doors are closed' but the conveyor won't run, walk the line and try to open every guard door with the lock switch key. If one door opens without the key, the interlock switch is defeated or broken. That's your culprit.

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