Hired-Hand Farm Hand Series: Vent Master 16 Stage - Manual (Page 21)

Part No. 4801-5098 Farm Hand Vent Master 18
the Tunnel On Stage (SWX-2) switch to off. You can then set the temperature at which you
would like to enter tunnel mode at P25 and the temperature at which you would like to exit
tunnel mode at P26. Otherwise, set the Tunnel On Stage (SWX-2) to ON.
12.4 Cool Timer Stage Operation
On the Farm Hand Vent Master any of the ON/OFF can be placed on a cool timer. A cool timer
stage will come on and run at the timer percentage whenever temperature is above it’s OffPoint
(Off), and its timer percentage will increase as temperature rises. The following graph shows
how you can vary this percentage.
Refer to Graph 1 and Table 1. The stage is placed on a cool timer by setting P3=2. A Cool
Timer stage always varies its runtime based on the stage's temperature and its ON and OFF
settings. In this example, the OffPoint is set to 80ºF (OFF=80), and the OnPoint is set to 86ºF
(ON=86). The stage will not run if the temperature is below the OffPoint, as shown in
Graph 1. When the temperature reaches the OffPoint, the stage is placed on the system timer.
To enhance temperature control, the Runtime percentage of a cool timer stage can be varied. The
percentage of the Runtime that the cool timer stage is ON can be varied when the temperature is
between the OffPoint and the OnPoint by setting parameters P70 and P71. In this example, the
Minimum Runtime percentage is 50%, as set by P71 = 50. The Maximum Runtime percentage is
90%, as set by P70 = 90.
When the temperature reaches 80º F the stage runs for 50% of the Runtime period (2-1/2 minutes
if the system timer is set for 5 minutes, or 5 minutes if the system timer is set for 10 minutes).
As the temperature increases, the Runtime percentage of the stage progressively increases up to
the Maximum Runtime percentage of 90% when the temperature reaches 86º F. Above 86ºF, the
Runtime percentage remains constant at 90%.
Table 1 Example Of Cool Timer Stage Operation
Brief Description Of Cool Timer Stage Operation
Setting Stage Sensor Stage Mode Stage Timer OffPoint OnPoint
Cool Timer
Max % Cool Timer
Min %
Parameter P1 P2 P3 OFF ON P70 P71
Value 10 02 02 80 86 90 50
Option Sensor 1 Cool Stir Timer ON
Minimum
OnPoint Maximum
OnPoint Maximum
Runtime % Minimum
Runtime %
75 80 85 90
Runtime Perc
entage
Graph 1 ON/Off Stages
86ºF
OnPoint
90
50
80º F
OffPoint
Temperature (F)