Pallet Wrapper Won't Start
A wrapper that won't initiate a cycle usually comes down to a safety system, not a mechanical fault. Safety gates, e-stops and guard interlocks are the first things to check - the machine is designed not to run when any of these are open or active.
Common symptoms
Whether the panel has power or not is the first thing to establish. Everything else follows from that.
Nothing happens when the start button is pressed
The panel may have power but no cycle initiates. A safety interlock or e-stop circuit is almost always the cause - the machine won't start until every condition in the safety chain is satisfied.
Panel is completely dead - no lights, no display
No power reaching the control panel. Check the supply back to the isolator before opening any panels. A tripped breaker or blown fuse is the most likely cause.
Safety alarm shows on the display but the cause isn't obvious
Most wrappers display which safety circuit has triggered. Check the alarm code or indicator before anything else - it will tell you which guard, gate or sensor is open.
Machine was running and stopped mid-cycle, now won't restart
A mid-cycle stop on a wrapper is often a safety trigger - something broke the safety beam or opened a guard during the cycle. The machine latches the alarm and won't restart until it's acknowledged and cleared.
Turntable rotates manually but the auto cycle won't start
Manual functions working while auto won't run typically points to a wrap program fault or a cycle-start interlock - the machine has power and drive but won't enter the auto cycle sequence.
Machine starts the cycle then immediately stops
Initiates and halts within the first second. Usually a safety beam that's been obscured, a guard that's vibrating open under acceleration, or a pallet that's breaking the safety perimeter on start-up.
Typical causes
Safety gate or guard interlock open
The most common cause. A gate, guard panel or safety door isn't fully closed, or the interlock switch has developed a fault. The machine will not start with any part of the safety perimeter open - by design.
Emergency stop engaged or faulty
An e-stop on the machine or the line is latched in. On wrappers with remote pendants, the pendant e-stop is easy to miss. A faulty e-stop contact can also hold the machine in a stop condition even when the button appears released.
Power supply fault
A blown fuse, tripped circuit breaker or faulty isolator is preventing power from reaching the machine. Often the supply appears fine at the wall but the machine's internal supply has failed - check the machine fuse before assuming an upstream fault.
Control system or contactor fault
The control PLC or a main contactor has developed a fault. Less common than safety-related causes, but more likely on older machines or those that have been running in a wet or dusty environment.
What to check first
Safety systems are deliberately designed to be hard to bypass. Work through them methodically rather than trying to force a start.
Walk every e-stop and safety gate
Release every e-stop button on the machine, including any on a remote pendant or at the line control panel. Check every safety gate and guard is fully closed and latched. One open condition in the safety chain will prevent start.
Check the display for an alarm code
Most wrappers show which safety circuit has triggered. Look for an alarm code or a flashing indicator light and note it down before pressing anything. The code tells you exactly which part of the safety system is open.
Check the supply and fuse
If the panel is completely dead, check the power supply from the isolator to the machine. Confirm the machine's internal fuse is intact. A blown fuse on a wrapper often points to something drawing excess current - don't just replace it without investigating.
Try manual mode first
Switch the machine to manual mode and test individual functions - turntable rotation, film carriage movement. If manual functions work but auto cycle doesn't initiate, the fault is in the cycle-start logic or a wrap program setting rather than the power or drive systems.
If any of these apply, don't wait
- All e-stops are released and all gates are confirmed closed but the machine still won't start
- The control panel is completely dead with confirmed supply at the isolator
- A safety interlock switch is suspected faulty - don't attempt to bypass it
- The machine stops immediately every time a cycle is initiated, regardless of load
Safety system faults on wrappers should never be bypassed to keep production running. If you've cleared all the obvious causes and the machine still won't start, it needs a proper diagnosis.