Hired-Hand Farm Hand Series: 4 Stage Controller - Manual (Page 13)

4801-5058 Rev 8-04 Farm Hand 4 Stage Controller 13 of 30
2. The next step in setting up your tunnel house is determining how your controller should
operate while out of tunnel mode. In other words, does your house always power
ventilate or does it naturally ventilate using curtain sidewalls. If it is a power ventilated
house you must set the Power Ventilate switch (SWX-7) in the on position.
3. The last step in setting up your tunnel house is determining how you would like to
initiate tunnel mode. You can initiate tunnel mode by outside temperature or by your
lowest programmed cool tunnel stage. The lowest programmed cool tunnel stage is
determined by the lowest onpoint. If you would like to tunnel based on outside
temperature you must set the Tunnel On Stage (SWX-6) 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-6) to on.
The following is a brief description of how the tunnel would work in each of the situations.
Tunneling on outside temperature in a naturally ventilated building
When the outside temperature rises above the Tunnel Onpoint (P25), the
controller will shut down all stages and begin to close the main curtain and
open the inlet curtain. After 1 minute has passed, the controller makes
sure that the inlet is open. If there is no error condition, the controller will
begin waiting for the main curtain to close. If the controller does not see
the main curtain closed after 12 more minutes, it will abort tunnelling, and
sound the alarm. Once the controller recognizes that the main curtain is
closed, it will then allow the other cool tunnel and cool negative tunnel
stages to come on. Once the temperature drops below the Tunnel Offpoint
(P26), the controller will open both the inlet and the main curtain fully and
return the stages to normal operation immediately.
Tunneling on a stage in a power ventilated building
As soon as the lowest programmed Cool Tunnel stage comes on, the
controller opens the inlet curtain and leaves all Cool Negative Tunnel and
Cool Tunnel stages on. When the temperature begins to fall and the lowest
programmed Cool Tunnel stage turns off, the controller will close the inlet
fully and return the stages to normal operation immediately.
Tunneling on outside temperature in a power ventilated building
The controller reacts in the same way as in the previous example, except it
uses P25 and P26 to enter and exit tunnel. For proper operation in a house
without a curtain sidewall, you must jumper the curtain closed switches on
the main curtain together.
9.3 Cool Timer Stage Operation
On all 4 Stage Controllers, any of the 4 ON/OFF stages 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 (P5), 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 P4 and P5
settings. In this example, the OffPoint is set to 80ºF (P5=80), and the OnPoint is set to 86ºF
Note: If you are using a main sidewall curtain, it must run at a speed where it
can go from fully open to fully closed in less than 13 minutes. If not, the
controller will not operate properly as tunnel.