May 29, 2018
The following are general troubleshooting tips for primary and secondary reeling devices.
If alarms occur repeatedly, the timeouts should be increased. If the alarm remains active, there is a physical fault in the machine.
Probable cause: The device has not moved away from the limit switch, although the control is on.
Correction: Check whether the control reaches the valve, i.e. whether the LED on the valve cap is on. If the LED is on, there is a malfunction in valve or hydraulics. Check the valve coil. If the LED is not on, there is an electrical fault. Check the fuse, relay, and wiring.
Probable cause: The device has moved away from the start limit, but it has not reached the end limit.
Correction: Check whether the movement has been mechanically completed. If the movement is not completed, check whether there is a mechanical obstacle. If the movement is completed, check whether the limit switch flag has been bent and whether the limit switch functions.
Probable cause: The program does not know if the device has moved, because the device has not reached the limit switch.
Correction:
Probable cause: Limit switch flag is distorted.
Correction: Repair the limit switch flag and check the limit switch function.
Probable cause: There is too much material on the locking clamp tips. The locking clamps rotate the bearing housing of the reel spool when the locking clamps open.
Correction: On grounds of the wear mark, material is ground away from the locking clamp tips.
Probable cause: The down position of the primary reeling device has been incorrectly adjusted, either too low or too high.
Correction: Adjust the down position according to OEM instructions.
Probable cause: The mechanically-controlled safety valve is causing disturbance.
Correction: Align the wear pieces acting as guide surfaces and the mechanical control lever of the valve.
Probable cause: The linear load reference value is not sufficient to close the nip because the frictions or zero points have changed.
Correction:
Probable cause: The fault is related to relief calculation. For example, the calculated paper mass may be incorrect in the load relief calculation.
Correction: Check the measurements and masses used in calculation.
Probable cause: Nip closes askew or at a too high speed.
Correction: Readjust the nip closing speed.
Probable cause: Nip closes with excessive force.
Correction: Decrease the nip closing linear load value.
Probable cause: The paper is too dry.
Correction: Check the paper moisture content and adjust it to be correct.
Probable cause: The interlock enabling the movement fails to become active.
Correction: Find the missing interlock on the Help display or the ladder logic. The preventing interlock may be caused by a loose limit switch or limit switch flag.
Probable cause: Primary center drive does not make an engagement rotation. Cogs hit against each other and the coupling cannot close.
Correction:
Probable cause: Limit switch or limit switch flag is loose or damaged.
Correction: Check the operation of the limit switch.
Probable cause: The hydraulic pressure reducing valve is adjusted incorrectly.
Correction: Adjust the pressure reducing valve in accordance with the hydraulic diagrams. Use a pressure gauge for this purpose.
Probable cause: The coupling and reel spool are not aligned with each other.
Correction: Check the coupling alignment. The primary reeling device must be in up position and coupling engaged. Rotate the coupling back and forth manually; there should be a clearance. If there is no clearance, align the coupling according to the instructions.
Probable cause: Speed sync is missing from the drives.
Correction:
Probable cause: The losses in the calculation of the electric drives are erroneous.
Correction:
Probable cause: The interlock enabling the movement fails to become active.
Correction: Find the missing interlock on the Help display (if available) or ladder logic. Preventing interlocking may be the result of a loose limit switch or limit switch flag.
Probable cause: Angle measurement is out of range or there is an I/O fault.
Correction: Check the operation of the angle measurement and set the zero point according to the instructions.
Probable cause: Power failure.
Correction: Measure the power supply voltage and control voltage of the valve from the terminal blocks, from which the device cable runs to the valve cap. If the voltages are not found, check and repair the electric circuit using the circuit diagram.
Probable cause: Hydraulic or valve fault.
Correction:
Probable cause: The mechanical stopping pieces are too high.
Correction: Re-shim the stopping pieces according to the instruction.
Probable cause: The reference value for turning speed is insufficient for slow turning.
Correction: Increase the reference value for slow turn on the tuning page or in ladder logic. However, the reference value must be so low that the primary reeling device does not drop heavily onto the rails.
Probable cause: Angle measurement or the lower limit switch stops the turning, but the directional control valve does not open.
Correction: Check the directional control valve coil/control with a magnetic pen. Replace the coil or valve, or repair the possible electrical fault.
Probable cause: The value of the deceleration angle is too high.
Correction: Decrease the deceleration angle value on the tuning page or in the ladder logic.
Probable cause: The value of the turning stopping angle is too high.
Correction: Decrease the value of the turning stopping angle on the tuning page or in the ladder logic.
Probable cause: The reference value for turning speed is too high for a slow turn.
Correction: Decrease the reference value for a slow turn on the tuning page or in the ladder logic. However, the reference value must be so high that the primary reeling device moves.
Probable cause: The angle value does not change sufficiently within the set monitoring time.
Correction: Check the angle value on the display and whether it corresponds to reality. Check the operation of the angle measuring sensor. The magnet of the angle measuring sensor may be loose or twisted.
Probable cause: This results in a measurement peak that stops the turning.
Correction: Check the angle value on the display and whether it corresponds to reality. Check the operation of the angle measuring sensor. The magnet of the angle measuring sensor may be loose or twisted.
Probable cause: The turning movement does not keep in sync and stops aslant at the angle.
Correction: Adjust the lengths of the rigging screws according to the OEM instructions.
For assistance troubleshooting your reel operations, contact your Valmet representative.