Nexen TCD600E 912145 - Manual (Page 22)

FORM NO. L-20348-F-0705 22
UNWIND APPLICATION
With a full roll on the unwind shaft, the Start contact or button
is momentarily closed or pressed to put the TCD600 into Start
operation at the same time the machine begins pulling the web.
During the Start operation, which lasts for the duration of the Start
Time (see figure 39), TCD600’s output is at the Hold Torque value
that was set as one of the Job parameters. The purpose of the
Start value and Timer is to keep the brake torque low while the roll
accelerates, thus preventing the web from being over-tensioned
during acceleration.
After the Start Timer has expired, the TCD600 enters Automatic
Operation. The output level is a function of the roll diameter and
the setpoint percentage. As the roll unwinds, the output level will
decrease in order to maintain constant tension. If the Hold/Re-
sume contact is closed or the Hold/Resume button is pressed,
the output level will remain constant until the contact is opened
or the button is released, allowing the TCD600 to return to Auto-
matic Operation.
When the Stop contact is momentarily closed or the Stop button is
pressed, the TCD600’s output will increase by the number of times
set in Stop Mult as one of the Job parameters. This increased level
will be maintained for the duration of the Stop Time to provide the
additional braking torque needed to decelerate the roll. After the
expiration of Stop Time, the output level will return to the value it
had before the stop. If the Hold/ Resume contact is then closed
or the Hold/Resume button is momentarily pressed, the output
level will remain at the pre-stop value for the duration of the Start
Time. However, if the Start contact is closed or the Start button
is momentarily pressed, the output level will change to the Hold
Torque value for the duration of the Start Time.
contact is closed or the Hold/Resume button pressed, the output
will remain constant until the Hold/Resume contact is opened or
the button is released allowing the TCD 600 to return to Automatic
Operation. This is used when winding is interrupted once or several
times per roll winding.
When the Stop contact is closed or the Stop button is momen-
tarily pressed, the TCD 600’s output will remain constant at its
present value. The machine is decelerated to a complete stop. If
the Hold/ Resume contact is then closed or the Hold/Resume
button is momentarily pressed, the output level will remain at
the pre-stop value for the duration of the Start Time. If the Start
contact is closed or the Start button is momentarily pressed, the
output level will change to the Hold Torque value for the duration
of the Start Time.
FIGURE 40
FIGURE 39 UNWIND APPLICATION
WINDING APPLICATION
OPERATION (continued...)
Output Level
Start Contact
Web Speed
Hold/Resume Contact
Stop Contact
6
3
4
5
1 1
2
1. Hold Torque
2. Start Time
3. Automatic Operation
4. Hold Operation
5. Stop Operation
6. Stop Time
3
2
Output Level
Start Contact
Stop Contact
Web Speed
Hold/Resume Contact
1
2 2
3
4
5
4
6
1. Minimum Output
2. Hold Torque
3. Start Time
4. Automatic Operation
5. Hold Operation
6. Stop Operation
WINDING APPLICATION
NOTE: For winding applications that use a mechanical clutch,
the minimum output level can be set to overcome the me-
chanical characteristics of the clutch, e.g. a release spring.
See Calibration Mode CAL MIN OUT for the set up procedure.
Otherwise the minimum output level should be set to zero for
instances when a mechanical clutch is not used.
When the Start contact is closed or the Start button is momentarily
pressed, the TCD 600 goes into Start operation for the duration
of the Start Time (see figure 40). The output level changes to the
Hold Torque value that was set as one of the Job parameters.
The clutch begins to rotate and take up slack from the web. The
machine begins to accelerate.
After the Start Time has expired, the TCD 600 will enter Automatic
operation and output will increase steadily as a function of the
roll’s diameter and Setpoint (and Taper setting, if required). As the
roll winds, output level will increase in order to maintain constant
tension. If taper tension is needed rather than constant tension,
use the Taper Tension setting to decrease the tension as the roll
increases in diameter. See "Overview" in OPERATION section
for a description of Taper Tension. Whenever the Hold/Resume