Grain Systems PNEG-1743 - Manual (Page 41)

6. Moisture Control Options
PNEG-1743 Vision for Tower Dryers 41
Variable Moisture
When to Use:
For use when minimum moisture management is available and when large, quick changes in moisture are
not expected. Can be used during all heat and dry and cool operation.
How it Works:
The user should stabilize the dryer with the Unload switch in the “MANUAL” position. It is imperative that
the dryer is outputting the desired moisture content grain before switching the unload to the “AUTO”
position. Within one minute of switching the unload to “AUTO”, the dryer uses the current state of the
sensors as a reference for future adjustments. The dryer will then run through a 30 minutes learning period
and controller adjustments will begin after.
The controller continuously monitors the moisture coming in and out of the dryer and the column grain
temperature 2/3 of the way down the dryer. The control action is mainly based on the dry moisture sensor
at the outlet of the dryer. If the moisture coming out of the dryer is not right at the target, the controller will
speed up or slow down the unload rate accordingly. The wet moisture sensor and the grain temperature
sensor are intended to detect moisture spikes coming into the dryer so that the moisture controller can
react ahead of time. For example, if the wet sensor detects a jump of moisture coming into the dryer, the
controller will start slowing down the unload speed immediately. However, the controller does not act to
the full scale right away. Instead, it slows down the dryer gradually so that the grain currently in the dryer
will not be over-dried.
NOTE: The wet moisture sensor can be disabled in this scheme. The wet moisture reading reported will
be ignored by the calculations.
NOTE: A “Max Grain Temp” safety is available for this scheme. By enabling this feature, the dryer will
shutdown and issue a warning if the grain temperature exceeds the “Max Grain Temp” value.
Setup Procedure
1. Press the “Stop” button on the control panel if the dryer is running.
2. From the “Setup” screen, select “Drying Mode”, then “Continuous Flow”.
3. From the “Drying Mode Selection” screen, select “M/C Setup” to access “Continuous Flow Setup”.
4. Select “Moisture” from the “Continuous Flow Control Schemes” group.
5. If desired, enable the “Max Grain Temp” safety.
6. Select “Variable” from the “Moisture Based Options” group.
7. If desired, enable/disable the “Upper Moisture Sensor”.
8. Return to the “Default Operation Screen”.
9. Turn the “Unload” switch to the “MANUAL” position.
10. Press the “Start” button on the control panel.
11. Press the “Meter Roll Speed” adjustment knob to access the “Modifying Meter Roll Speed
Setpoints” screen.
12. Adjust to desired speed and press “Accept/Exit”.
13. Wait at least 30 minutes, depending on the size of the dryer and check for consistent dry moisture.
If moisture is not consistent, repeat Steps 11 and 12 .
14. If you have made it here, the grain must be exiting consistently. If not, return to Step 11 .
15. Turn the “Unload” switch to the “AUTO” position.