Pallet Wrapper Running Slowly or Stalling
Reduced speed on a pallet wrapper is usually a drive parameter, an overload condition, or mechanical drag that's developed gradually. Whether it's the turntable, the carriage, or both running slowly helps identify which drive and which system to check first.
Common symptoms
Note whether it's the turntable, the carriage, or both running slowly, and whether the speed drop appeared suddenly or gradually. Those two details narrow the cause significantly.
Everything runs slower than normal
If both the turntable and carriage are running below normal speed, the most likely cause is a speed reference that's been changed in the program, or a global machine setting that's been altered. Check cycle time against what it should be and whether any settings changes were made recently.
Only the turntable is running slowly
Isolated turntable slowdown points to the turntable drive specifically - an inverter parameter change, the drive running in current limiting due to load, or mechanical drag under the turntable. If speed varies with load weight, the drive is limiting rather than a setting being wrong.
Only the carriage is running slowly
Carriage-only slowdown points to the carriage drive, the mast and guide system, or a belt or chain component that's stretched or wearing. Check whether the carriage slows at specific points in its travel or uniformly across the full stroke.
Speed drops under heavier loads
A machine that slows noticeably when the load is heavy but runs normally with lighter loads is almost certainly hitting the drive's current limit. Either the load is at the edge of the machine's rated capacity, or the drive's performance has reduced due to a component issue.
Speed was normal then gradually reduced over time
Gradual slowdown over weeks or months usually means mechanical wear - a bearing, a drive component, or lubrication failure creating increasing drag. The drive compensates for a while, then runs in current limiting, then eventually trips. It rarely presents suddenly.
Machine stalls under load then needs a reset
A stall - where the machine stops under load but restarts after a reset - means the drive has tripped on overload. The drive stopped the machine deliberately to protect itself. Read the fault code on the inverter before resetting to understand what triggered the trip.
Typical causes
Drive speed parameter changed
The simplest cause of reduced speed is a speed reference that's been lowered in the program or drive parameters - intentionally or accidentally. If speed dropped after someone adjusted settings, this is the first place to look. Compare the current speed setting against the machine's original commissioning specification.
Drive running in current limiting or thermal overload
An inverter that's working harder than it should - due to mechanical drag, a heavy load, or a motor that's starting to degrade - will reduce its output frequency to limit current draw. The machine runs but at reduced speed. The inverter display may show an overload warning even if it hasn't tripped yet.
Mechanical drag from wear or obstruction
Worn bearings, inadequate lubrication, debris under the turntable, or a drive component that's degraded all create drag that the drive has to work against. The drive compensates by drawing more current, which causes it to run in limiting or eventually trip. The mechanical load is the root cause, not the drive itself.
Load exceeding the machine's rated capacity
A consistent pattern of loading at or above the machine's rated weight will cause the drive to run at reduced speed to manage torque demand. The machine runs but can't maintain the programmed speed. This is more common when a machine is used for load types it wasn't originally specified for.
What to check first
Time the cycle against what it should be to confirm the speed drop is real. Then check whether it's load-dependent - that distinction tells you whether it's a setting or a mechanical issue.
Check speed settings in the program
Go into the wrap program and check the configured turntable speed and carriage speed against the machine's normal operating settings. If the speed has been reduced - even slightly - that's the likely cause. Also check whether the machine is running the correct program number for the load type.
Run with a light load and compare
Run the machine with the lightest load available and time the cycle. Then run with a normal production load and time it again. If the light load runs at normal speed but the heavy load runs slowly, the drive is limiting on current - the cause is load or drag, not a settings issue. If both run slowly, it's a setting or a drive parameter.
Check inverter displays for warning conditions
Check the turntable and carriage inverter displays during a running cycle - not just when faulted. Some inverters display a warning or status indicator when running in current limiting or approaching thermal overload. This appears as a reduced-speed run rather than a trip, but the inverter knows it's happening.
Check for mechanical drag with the machine isolated
With the machine isolated, check whether you can rotate the turntable by hand - it should turn freely with minimal effort. Also check under the turntable for debris or film accumulation. For the carriage, try moving it manually along the mast - any resistance you feel is mechanical drag the drive is fighting against during production.
If any of these apply, don't wait
- Speed has reduced gradually over time and the cause isn't a settings change
- The machine stalls under normal production loads
- There's visible resistance when you try to turn the turntable or move the carriage by hand
- The inverter is showing overload or thermal warnings during normal operation
A drive running in sustained current limiting is working harder than it should. Left unresolved, thermal stress accumulates and the drive degrades faster than it would under normal load. Mechanical drag identified early is usually straightforward to address.