4.
If either the left or right bed safety temperature switch opens, a
REGEN TEM SAFETY
is
generated. The alarm horn and light are activated. The process heater, regen heater, and
process/regen blower are turned off. Pressing the
ALARM SILENCE
button on the touch screen
will deactivate the alarm horn and light.
5.
Turn the
Off-On
switch to the
ON
position and push the touch screen
START
button to restart the
dryer. If the switch is still open, the dryer will not restart.
6.
If the PLC/touch screen faults, the optional redundant high temperature safety device opens, or the
process heater safety switch opens, a process heater fault is generated. The alarm horn and light are
activated. The process heater, regen heater, and process/regen blower are turned off. Pressing the
ALARM SILENCE
pushbutton will deactivate the alarm horn and light.
7.
Turn the
Off-On
switch to the
ON
position and push the
START
button to restart the dryer. If the
fault condition still exists, the dryer will not restart.
8.
If the process blower overloads trips, a
PROCESS BLOWER FAIL
is generated. The alarm horn
and light are activated. The process heater, regen heater, and process/regen blower are turned off.
Pressing the
ALARM SILENCE
button will deactivate the alarm horn and light.
9.
Reset the motor overload and turn the
Off-On
switch to the
ON
position and push the
START
button on the touch screen to restart the dryer.
10.
The valve position limit switch enables the right bed heater and provides an input signal to the PLC
when actuated by the cam lobe. Each heater is controlled by the PLC.
11.
Upon completion of the
HEAT
portion of the regeneration sequence, the regen heaters are disabled
by the PLC and the
COOL
time begins.
12.
Once the
COOL
time has expired, the valve motor is turned on until the cam switch makes a
transition. Upon making a transition, the timing sequence is restarted for the new bed.
13.
When a
HIGH DEW POINT
alarm is generated by the dew point controller, the alarm horn and
light will activate. Press
ALARM SILENCE
to deactivate the alarm until the next
HIGH DEW
POINT
alarm occurs.
14.
The dryer is shut off by pushing the
SHUTDOWN
button on the PLC or turning the control power
On/Off
switch to the
OFF
position.
15.
Refer to the schematic drawing enclosed in the control enclosure.
4-3 Shutting Down the Dryer
1
Turn off the conveying system supplying the drying hopper and/or machine. Press the
SHUTDOWN
button for the dryer to complete its cycle.
2
When processing is complete, close the hopper slide gate and shut down any in-line companion
equipment, such as the aftercooler.
3
If the dryer is shut down using the
SHUTDOWN
button on the dryer status screen, the process
heater will shut off and the bed regeneration process will be completed. When the dryer is started at a
later date the process air will be directed through the bed that was regenerated last.
4
If the dryer control switch is turned off without using the dryer shutdown feature, the dryer and the
on board conveying system will stop immediately. When the dryer is started at a later date, the
process air will be directed through the last bed that was being used when the dryer control switch
was turned off. If a bed was being regenerated when the dryer control switch was turned off, the
regeneration process would begin over again on that same bed.
Portable Drying/Conveying Systems
Chapter 4: Operation
39 of 63
