1592015820 User manual IC260_261L_D DUO FW1.9 rel. 1.0
Pag. 97 of 149
Parameter Description
min
max
udm
FS21
Temperature differential to enable the freecooling function
0
25.0
45
°C
°F
FS22
Temperature differential for the free cooling regulation
0.1
0
25.0
45
°C
°F
….
FS34
Free cooling water pump OFF time if chiller only Free cooling
0
250
min
FS35
Free cooling water pump ON time if chiller only Free cooling
0
250
sec
FS36
Free cooling maximum time
0
250
min
FS37
Set point Free cooling
-50.0
-58
0.0
0
70.0
158
50.0
725
°C
°F
bar
psi
FS38
Proportional band Free coling
0.1
0
0.1
1
25.0
45
14.0
203
°C
°F
Bar
Psi
FS39
Minimum value Free cooling analog output
0
100
%
FS40
Maximum value Free cooling analog output
0
100
%
FS41
T1 probe selection for Free cooling
0=disabled, 1=Pb1, 2=Pb2, etc.
0
10
FS42
T2 probe selection for Free cooling
0=disabled, 1=Pb1, 2=Pb2, etc.
0
10
FS43
Outside temperature set point to force the maximum speed of
condenser fan
0
1
Only free cooling for cooling (CF97=2)
Compressors are not used for cooling.
Evaporator and condenser water pumps are managed according to chiller probe and St01 set point;
free cooling valve/pump is managed according chiller probe and FS37 set point (or St01 if
St01<FS37).
If the free cooling set point is not reached in FS36 minutes (0 = function disabled) or when the free
cooling set point is reached, the free cooling will be disabled for FS34 minutes.
After this time the valve/pump is switched on for FS35 seconds and, when this time is elapsed the
controller verify if T1 temperature – T2 temperature
FS21 and if free cooling temperature > FS37.
If both condition are true, the free cooling valve/pump is activated.
If FS34=0 and FS35=0 this function is disabled.
Compressors and free cooling used for cooling (CF97=2)
Compressors are managed as standard chiller regulation.
Free cooling valve/pump is managed according chiller probe and FS37 set point (FS37 has to be set
>St01); the regulation is done like figure above.
