Graco PD44 Setup And Operation page 26

HMI Operation
Enter Purge Time Button
The Enter Purge Time button is shown as "=000.0"
below the Purge Timer On /Off button. The Enter Purge
Time button allows the operator to set the required time
between cycles. When the Purge Timer switch is in the
ON position and the Pump Mode switch is in the Shot or
Operator Control position, the purge timer unit counts up
to the preset time. When it reaches the preset time, a
purge shot is initiated.
The timer then automatically resets and continues with
the sequence of cycling and resetting. It continues until
the Purge Timer is turned to the OFF position.
To change the Purge Timer setting, perform the follow-
ing steps.
1. Select Purge Timer button. A numeric keypad
appears.
2. Enter the desired purge time in seconds. Use the "."
button to enter tenths of a second.
3. Press the button. The Purge Timer screen
appears. The new purge time appears in the Purge
Timer button.
NOTE: The current Purge Timer time is shown in the
bottom text box below the Purge Timer button.
Calculating the Purge Timer Setting
If the shot size is larger than the mixer volume, set the
timer for one-half the gel time of the material. If the shot
size is smaller, use the following formula to determine
the Purge Timer setting.
Gel Time X Shot Size
2 X Mixer Volume
For example, with mixer volume = 13.3cc, shot size =
10cc, gel time = 10 minutes, use the following equation.
10 min X 10 cc
=
2 X 13.3 cc
26
= Timer Setting
100 cc*min
= 3.76 min
26.6 cc
Dwell / Alarm Timer
Always set the dwell/alarm timer to a value that will
give the user adequate warning that the machine is
about to dispense a purge shot.
This changes the duration that the audible alarm is
active prior to the purge shot being initiated.
To change the Dwell Timer, perform the following steps.
1. Select the Dwell Timer button. A numeric keypad
appears.
2. Enter the desired Dwell Timer time in seconds. Use
the "." button to enter tenths of seconds.
3. Press the button. The new Dwell Timer time
appears in the Dwell Timer field.
NOTE: The current Dwell Timer time is shown by
<000.0.
Purge Shot Size % button (LRT and Motor Driven
PD44 only)
This button shows the Shot Size volume in percent of
stroke. This volume is dispensed during the ratio check.
To change the Purge Shot Size % volume, perform the
following steps.
1. Select Purge Shot Size % button. A numeric keypad
appears.
2. Enter the desired material shot size volume.
3. Press the button. The Purge Timer screen
appears. The new shot size percentage appears in
the Purge Shot Size % field.
Number of Strokes During Purge button/indicator
(LRT and Motor Driven PD44 only)
This displays the number of strokes used during the
purge shot.
For example, if the purge shot size is set at 150%, Num-
ber of Strokes During Purge displays "2" and Amount
Per Stroke % displays "75".
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