Grain Systems PNEG-1935 - Manual (Page 40)

6. Moisture Control Options
40 PNEG-1935 Vision Hybrid for Portable Dryers
5 Speed Temperature
When to Use:
For use with a wider moisture variation spread and for when a close and quick reacting moisture control
is desired in all heat or 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.
There are five Speeds associated with this drying scheme, but the user only selects one unload rate.
The meter roll setpoint is used as the middle or medium speed. The other four Speeds are offsets of the
medium speed, two higher and two lower. These offsets are labeled as follows: Low (LO), Medium-Low
(M-LO), Medium (MED), Medium-High (M-HI) and High (HI). The unload rate is determined by the
difference between the grain temperature setpoint and the actual temperature sensor reading. If the
reading is exactly that of our temperature setpoint (a zero offset), MED would be selected, because
we must be at the correct speed.
When setting up the 5 Speed Temperature scheme, there are two (2) sets of parameters: “Inner” and
“Outer”. Both have a temperature and a meter roll speed associated with them. “Inner” refers to the M-LO
and M-HI speeds, while “Outer” refers to LO and HI.
Let’s pretend we have the parameters set as they are presented in the following table.
We will set the meter roll setpoint to 50% and grain temperature setpoint to 100° for convenience. If the
grain temperature actually is 100°, the MED unload would be selected (50% in our example). Should the
grain temperature climb to 101°, the controller will change to M-HI, which increases the unload rate by 3%.
Now the dryer’s unload is running at 53% (50% + 3% = 53%). If the grain temperature continues to climb,
reaching 103°, HI will be selected which increases the unload rate by 12%. This 12% increase is in relation
to the MED speed, NOT the M-HI, so the unload rate is now at 62% (50% + 12% = 62%). If the grain
temperature falls back below 105°, the controller changes back to M-HI.
The same is true for grain temperatures below the setpoint, only the values are subtracted rather than
added. If the grain temperature falls to 99°, the controller will select M-LO, changing the unload rate to
47% (50% - 3% = 47%).
The following table depicts how the controller would act when setup as the example above.
NOTE: These are not necessarily the values that should be used with this scheme; these numbers were
chosen strictly for explanation purposes.
Inner (M-LO and M-HI) Outer (LO and HI)
Temperature 1° 3°
Meter Speed Offset 3% 12%
LO (Outer) M-LO (Inner) MED M-HI (Inner) HI (Outer)
Grain
Temperature
Less than or
equal to 97°
Between 98°
and 99°
At 100°
Between 101°
and 102°
Greater than or
equal to 103°
Unload Rate 38% 47% 50% 53% 62%