Hired-Hand Farm Hand Series: Vent Master 16 Stage - Manual (Page 24)

Part No. 4801-5098 Farm Hand Vent Master 21
12.5.2 Progressive Cool Timer Option
The progressive Cool Timer operation varies the Runtime percentage while keeping the fan speed
constant. Refer to Graph 3 and Table 3. The stage timer is set to ON (P3=2). In this case, the
stage timer setting is P3=2 to indicate progressive cool timer operation.
As in the previous example, the Maximum OnPoint is set to 80ºF (ON=80), and the Minimum
OnPoint is set to 75ºF (OFF=75). The Runtime percentage is progressively varied over this
temperature range from 75º to 80º. The "Var/Timer Pct." parameter, which in this case refers to
the stage's minimum runtime percentage, is set to 50 (See Section 5.1)
At 75ºF and below, the stage will operate at full speed on a system timer running at its minimum
runtime percentage (Var/Timer Pct. = 50). As the temperature increases above 75ºF so does the
stage's runtime percentage. Once the temperature rises above 80ºF, the stage will run
continuously.
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Brief Description Of Progressive Cool Timer Option
As you can see from graph 3, as the temperature increases above the Minimum OnPoint,
(OFF=75ºF) the Runtime % progressively increases until it reaches 100% at its Maximum
OnPoint (ON= 0ºF). When using this option, it is not necessary to set P10 or P11 for the stage.
These parameters only apply to variable speed operation.
13. Maintenance
Check the calibration of your sensors at least once per quarter. You will need to have two people: one
person at the sensor with a trusted thermometer, and one at the controller to set the sensor to the proper
setting.
100
50
50
100
76 78 80 77 75 79
Graph 3 Progressive Cool Timer Option
Maximum
OnPoint
TEMPERATURE (F)
Minimum
OnPoint
Table 3 Progressive Cool Timer
Option
Setting Stage
Sensor Stage
Mode Stage
Timer Minimum
OnPoint Maximum
OnPoint Minimum
Runtime % Motor
Curve Var/
Timer %
Parameter P1 P2 P3 OFF ON P10 P11 N/A
Value 10 02 02 75 80 N/A N/A 50
Option Sensor 1 Cool Stir Timer ON Stage begins
varying
Runtime Stage runs
continuously N/A N/A Refer to
Section
5.1