Pallet stretch wrapper troubleshooting guide, stretch wrap machine technical service.

PROBLEM	CAUSE	SOLUTION
AUTOHEIGHT DOES NOT WORK	Autoheight photoeye is out of adjustment	Check photoeye adjustments with the electrical schematics. Then check the sensitivity of the photoeye and re-align.
	Autoheight function switch is turned off on the control panel.	Turn the Autoheight function switch on.
	Photoeye is dirty.	Clean the photoeye light emitter.
	The color of the load is black or non-reflective	Increase the photoeye sensitivity enough to see the load without seeing something else when photoeye clears the load. If the problem persists an laser sensor may be necessary to replace the photoeye.
PRESTRETCH MOTOR NEVER STOPS TURNING	The steel cam is not close enough to the analog sensor when the dancer bar is at rest position. (For 200 & 300 models)	Turn the cam closer to the analog sensor or move the analog sensor toward the cam. The analog sensor and cam are situated under the red cover of the film carriage. See ANALOG SENSOR ADJUSTMENT.
	The set screw securing the film tension potentiometer on the dancer arm has come loose. (For 150 models)	Remove carriage cover and reset potentiometer to zero with dancer arm at rest. Secure shaft of potentiometer with set screw.
	The film tension potentiometer is defective. (For 150 models)	Remove carriage cover, locate potentiometer and replace with new one.
	VFD parameters may have been modified	Obtain an updated parameter listing from us and double-check all parameters in your VFD.
	The pre-stretch VFD may be defective.	The analog input voltage to the VFD must be 0Vdc when dancer arm is at rest. Use your multimeter across terminals 2 & 3 of the VFD to verify this. If you obtain a reading of 0Vdc, then your VFD is defective.
FILM IS TOO LOOSE ON LOAD	The film tension adjustment potentiometer located on the control panel is set too low.	Increase the film tension setting on the control panel.
	The pre-stretch or main drive belt or chain has broken.	Remove carriage cover and replace the corresponding belt or chain.
	The gap between the pre-stretch rollers and the aluminum rollers is too large.	Loosen the bolts securing the pre-stretch roller bearings (top and bottom). Adjust the gap so that it is uniform from top to bottom. The size of the gap will depend on the gauge of film that you are using.
TOO MUCH TENSION ON THE FILM / FILM BREAKING	The film tension adjustment potentiometer located on the control panel is set too high.	Reduce the film tension setting on the control panel.
TOO MUCH TENSION ON THE FILM / FILM BREAKING	Pre-stretch VFD is not running or may be faulted.	When cycle starts, observe reading on pre-stretch VFD…you should see a varying frequency being displayed. If a fault is present i.e. Fxxx, then shut-down the main power for 20 seconds and retry. If problem persists, see Control Panel trouble-shooting guide.

Wulftec NTPS Carriage Guide
ANALOG SENSOR ADJUSTMENT

Replacement and / or adjustment of the analog sensor and cam

Activate the Emergency Stop.
Remove the carriage cover.
Ensure that the dancer bar is fully retracted to home position.
By using a straightedge, and loosening the cam holding bolt, align straight side of cam with side edge of analog sensor holding bracket. Tighten bolt to secure cam in position.
Adjust the sensor by making light contact with the cam (a .005" gap is acceptable). Tighten the two (2) jam nuts to secure analog sensor in position.
Make sure the sensor's gap between the cam is not more than .005-. 010 to cam.
Replace the carriage cover.
Release Emergency Stop.
Leave the dancer bar at rest position and adjust the "span" potentiometer (pot 2) to it's maximum position (counter-clockwise).
Leave the dancer bar at rest position and adjust the "zero" potentiometer (pot 1) to it's minimum position (clockwise).
You need to reach a 0Hz frequency on the pre-stretch drive. If not, adjust the "zero" potentiometer (pot 1) to read 0Hz on the drive (this should be a clockwise adjustment). Leave it at the point where it is approximately 0Hz when adjusted.
Ensure that the pre-stretch motor does not run when the dancer bar is at rest position.
Move the dancer bar to it's maximum position.
Adjust (pot-2) to read 60Hz on the pre-stretch drive (this should be a counter-clockwise adjustment). Leave it at the point where it is approximately 60Hz when adjusted.
End of procedure.

NOTE: If 0 Hz from step 11 can't be achieved, slightly increase the gap between the analog sensor and the cam; following steps 1 through 5

Carriage Troubleshooting

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WULFTEC NTPS FILM CARRIAGE TROUBLESHOOTING GUIDE

WULFTEC NTPS FILM CARRIAGE
TROUBLESHOOTING GUIDE