Using the values
in the previous table,
the ventilation will run as follows.
Fan group1 will be used to supply the minimum ventilation.
As long as the house temperature is less then 26.5 degrees (function 02 plus function
04) the unit will run in the minimum ventilation mode. The fans will run 75 percent
(function 24) out of 10:00 minutes (function 19). In other words the fans will run in a
cycle of 7:30 minutes on, 2:30 minutes off.
How the calculation is made is explained as follows.
Th
e unit multiplies the total number of birds (function 22) by the current weight
(function 23) to get the total weight in Kg for the house = 15,000kg. This number is
then multiplied by the minimum amount of cubic air per kg (function 21) = 15,000
cube per hour. This gives us the total amount of cubic air per hour needed to supply a
minimum amount of air to the birds. Next we take into account the maximum amount
of air that fan group 1 can supply while per hour = 20,000 cube per hour.
We can now calculate the amount of time (function 24) that the fan 1 group needs to
run out of the fan cycle time (function 19) = 75 percent or 7 and a half minutes on 2
and a half minutes off.
As the weight increases (function 23) the fan duty cycle will increase. Once the du
ty
cycle reaches 100 percent fan 1 will run nonstop
If more than one group of fans is to be used there will be a 5 second delay between
the start of each fan group. The same delay time will be used when the fan groups go
off.
During the minimum ventilatio
n cycle the fan group 1 will be running in a cycle
mode. Before the fan group comes into operation the inlet will open to the set position
as programmed in function 11. Once the inlet has opened the fan group will come into
operation (after the 5 second de
lay). This cycle mode will continue to run as long as
the temperature is less then the required house temperature (function 02) plus the set
point for fan group 1 (function 04) = 26.5 degrees. Once the temperature in the house
rises to 26.5 degrees, the fan group 1 will run nonstop (if the duty cycle is less then
100%). If the temperature in the house reaches the set point of fan group 2 (function
05), then the inlet will open to the preset opening as set in function 12. Once the inlet
has opened fan group
2 will come into operation.
This mode will continue as explained, fans running and the inlet opening according to
preset positions.
Once the set point of the fan group that was programmed as the Tunnel group
(function 26) is reached the unit will open the cooling curtain to the set position
according to the programmed flap position. The inlet will be closed
According to the example this will happen when the set point for fan group 3 is
reached.
The fans will continue to operate during this transition. The
unit will continue to bring
into operation the fan groups according to the temperature increase.
Note: It is necessary to program the set points of the fan groups in a order
starting from fan group 1 through to fan group 7 .
Be sure that the programmed inlet/curtain opening for each group increases in
size in order to prevent a high (negative) static pressure in the house.
