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allow the operator to determine the proper tempera-
ture/moisture relationship. Using the Moisture Control
temperature display on the ASC panel, the operator
can view the current grain temperature and set the
desired grain temperature (set point), in the manner
described as follows.
NOTE: As previously stated, with the Unloading Switch
set to Manual, the Moisture Control can only display
grain temperature, but cannot control meter roll speed.
With Unloading Switch set to OFF, the Moisture Control
display is also off.
SETTING TEMP
a. Push DISP (display) button once and current set point
will be displayed as indicated by the letters SP (set
point) in the lower LH corner. See Fig. 3-1.
b. Raise or lower set point to desired temperature by
pushing the triangle buttons to increase or to decrease
(set-point range is 0-200°F).
c. Push RESET to return to measured temperature. SP
will not be displayed. If display is inactive for 60 sec-
onds, it will automatically return to measured tempera-
ture display. If moisture control is turned off while in the
SP mode, the newly entered set point will be canceled.
OPERATING WITH AUTOMATIC MOISTURE CONTROL
1. See Drying Tables in Section 5 for initial drying times
and initial % Unload Rates. Then start the dryer on
manual control.
2. Measure discharged grain moisture. If adjustments are
required, change the Manual Control Dial as required;
allow dryer to operate for one grain pass before
rechecking moisture.
NOTE: Time (min.) for one grain pass is as follows:
For dry/cool: Grain pass = Drying Time x 1½
For full heat: Grain pass = Drying Time
where Drying Time is found in the Drying Tables.
3. After the grain discharge has been readjusted and sta-
bilized at desired moisture content, note the tempera-
ture on the Moisture Control and adjust the set point to
the temp noted. Be sure to push the Reset button after
entering a new set point before proceeding.
4. Move the Unloading Switch from MAN to OFF, then to
AUTO, pausing 5 to 6 seconds in the OFF position.
This pause is necessary for the Moisture Control to
reinitialize. If the Moisture Control has been correctly
reinitialized, first zero degrees and then the correct
grain temperature will display after the switch is set to
AUTO. Failure to wait for a complete reset can cause
a lengthy delay in the time the Moisture Control needs
to arrive at the correct meter roll speed. Also impor-
tant: DO NOT CHANGE THE MANUAL UNLOAD
RATE WHILE IN THE AUTO MODE.
5. The Moisture Control unit will begin automatically con-
trolling the meter roll speed to compensate for changes
in the grain input moisture by maintaining the set point
temperature entered.
6. If large changes in grain input moisture are encoun-
tered, repeat the setup procedure to establish a new
set point temperature.
7. When restarting a loaded dryer following a shutdown
period, the dryer should be operated in the MANUAL
mode, until the newly dried grain has passed the RTD
grain sensor (2/3 of the grain pass time) and the grain
temperature has stabilized, before switching to the
AUTOMATIC mode. The Moisture Control set point
should not require readjustment.
See Section 5, Dryer Operation, for moisture control
operating procedure.
METER ROLL MONITOR SYSTEM
Operation - The meter roll monitor system is designed
to provide automatic shutdown of the dryer if the meter
rolls fail to rotate due to obstructions, malfunction, or
failure to turn the meter roll selector switch ON. The
monitor system functions only when the unload auger
circuit is energized, as required for normal meter roll
operation. See Fig. 3-2.
The main monitor system components are briefly
described as follows:
Proximity — The Meter Roll Proximity switch is mount-
ed on the unload auger drive end of the dryer, on the
same side as the auger motor. This switch senses the
rotation of the meter rolls and sends an electrical signal
to the meter roll monitor in the ASC control box.
(See Fig. 3-2, 6-9 and General Control Circuit in
Section 8.) The light on the switch indicates LOAD ON
each time a rotation has been sensed.
The proper switch adjustment is 1/8” to 1/4” clearance
between Proximity switch head and the rotating target.
The Proximity switch is slotted to allow readjustment, if
required. When properly adjusted, the LOAD ON indi-
cator will light every time the target rotates near the
proximity switch.
Meter Roll Monitor — The meter roll rotation is moni-
tored by the solid state Meter Roll Monitor Relay in the
ASC control box. The monitor is active whenever the
Unload Auger switch is in the AUTO position. If the
Monitor fails to see a change (either opening or clos-
ing) in the Proximity Switch signal within three minutes,
the safety circuit will be broken and the dryer will auto-
matically shut down. The Monitor resets automatically
when the control start button is pushed.
13
Fig. 3-2 Meter roll monitor
proxswitch.tif