EVCO c-pro nano CHIL - Manual (Page 121)

C-PRO NANO CHIL AND C-PRO MICRO CHIL – APPLICATION MANUAL
Pag. 121
PG13=1: SEPARATE AIR CIRCUIT
In the case of single condensation (PG11=1), or of separate condensation (PG11=0), having
two independent air circuits, no distinction is needed, as behaviour is identical. In this situation,
it makes sense to use parameter PS21 (free-cooling enable with compressors):
- PS21 = 0. If at least one compressor is switched ON, free-cooling is disabled; otherwise, it
follows normal ramp regulation.
- PS21 = 1. If at least one compressor is switched ON, the free-cooling ramp is forced to
maximum value (100% or other value set in parameter PS04); otherwise, it follows normal
ramp regulation.
Condensing fans is independent of free-cooling.
In order to activate the fan associated with free-cooling, it is also necessary to set to a value
different from 0 the position of the analogue output associated with parameter HA34.
6.14.3 Free-cooling control valves
In case the valve is of the ON/OFF type, the activation command will follow the consensus step on
FC set point, with hysteresis PS15, as previously described.
In order to enable the operation of the ON/OFF valve, it is also necessary to set to a value different
from 0 the position of the described digital output associated with parameter HA09.
Alternatively, it is possible to use a three-way modulating valve (0-10 V), to enable mixing of
evaporator inlet water, for a combined free-cooling action.
In this case, the valve is proportionally controlled, starting from the consensus step and until the
valve maximum-aperture threshold, corresponding to a percentage of the FC band (parameter
PS16).
In order to enable the operation of the valve, it is also necessary to set to a value different from 0 the
position of the analogue output associated with parameter HA19.
Inlet water temperature F-C set point
PS02
0 V
10 V
PS04
PS16
PS15