Hired-Hand Farm Hand Series: ST Temperature Controllers User Manual
Page 13
4801-5043 Rev 7/00
Farm Hand ST
12
Farm Hand 4-ST Example 1: All stages used as cooling with Mister ON (Refer to Graph 1).
For example, a farm manager determines that the target temperature should be 72
°
F. The target
temperature is set to 72
°
F according to the instructions in Section 6. The On Point of stage 1 is set
at 74
°
F. The timer percentage of stage 1 is set to 50% using the instructions of Section 8. The
manager then sets the On Point of stage 2 to 76
°
F, and the On Point of stage 3 to 78
°
F. In this
example stage 4 is used as cooling, and the On Point of stage 4 is set to 80
°
F. The Mister option is
set to ON and the run time is set to 40% using program parameters P6 and P7 (See Section 7.1,
Section 7.2).
Farm Hand 4-ST Example 2: Stage 4 used as heating. Mister OFF. (Refer to Graph 2).
A farm manager decides to reset the controller to allow heating if the house becomes to cool. The
farm manager also wants to protect against overheating inside the house. As in example 1 the
controller is set to a target temperature of 72
°
F. The On Points of stages 1,2, and 3 are set to the
same settings as in example 1 to protect against overheating. Stage 4 is reset for heating (See
Section 3, Adjust Switches). The On Point of stage 4 is set to 69
°
F. The heat will start at this On
Point temperature. Program mode parameter “P5” is set for 70
°
F. (Setting “P5” is discussed in
Section 7, Set Heat Off Points). The heat will shut off when the temperature reaches 70
°
F.
Farm Hand 4-ST
64 66 68 70
72
74 76 78 80 82 84
Degrees (Fahrenheit)
Stage 4
Stage 3
Stage 2
Stage 1
Stage 1
Stage 2
Stage 3
Stage 4
50%
All Stages Cooling
Timer % = 50%
Target = 72
Off Point
On Point
*
*
*
*
*
(Stage 1 Timer = 50%)
GRAPH 1
Stage
On
Point
Off
Point
1
74
°
F
Target Temp.
2
76
°
F
On Point Stage 1
3
78
°
F
On Point Stage 2
4
80
°
F
On Point Stage 3
GRAPH 2
Stage
On
Point
Off
Point
1
74
°
F
Target Temp.
2
76
°
F
On Point Stage 1
3
78
°
F
On Point Stage 2
4
69
°
F
P5 Shut Off
Important: The Off Point of a Cooling
stage N + 1 is automatically set the
same as the On Point temperature of
stage N. For Stage 1 the Off Point is
the Target
Temperature
.
Stage 4
Mister Run Time 40%
Farm Hand 4-ST
64 66 68 70 72
74 76 78 80 82 84
Degrees (Fahrenheit)
Stage 4
Stage 3
Stage 2
Stage 1
Stage 1
Stage 2
Stage 3
Stage 4
50%
Stage 1 Timer % = 50%
Stages 1,2,3 Cooling Target = 72
Stage 4 Heating
Off Point
On Point
*
* * *
*
Target = 72
P5 = 70