EVCO EPU2LXP1CH Installer manual - Manual (Page 70)

EVCO S.p.A. c-pro 3 micro CHIL | Application manual ver. 1.0 | Codice 144CP3CHE104
page 70 of 120
8.15 Free-Cooling Management
To obtain significant energy savings in the management of the system, the chiller has the possibility of using external air, when the air
has favourable thermal characteristics, to take advantage of its energy content and to obtain “free cooling”.
With free-cooling versions, a water coil is generally placed in front of the condenser coil (so that the air first flows past the water coil
and then the condensercoil);
when the external air temperature is lower than that of the water (and it is therefore possible to cool the water at the expense of the
external air), the water (or glycolmixture) that enters the machine is diverted onto the water coil by means of a three-way valve or by
means of a specific pump before passing through the evaporator.
There is also the possibility of having a separate free-cooling circuit with a fan dedicated to this purpose (PG13=1,2), allowing for better
control of condensation while the compressors are on and, at the same time, for regulating the ventilation of free-cooling.
8.15.1 Enabling of Free-Cooling
The function of free-cooling (FC), if configured according to parameter PS01, is enabled when the ∆T free-cooling (or the difference
between the temperature of the inflowing waterTInFCand the external temperature that affects the exchanger of free-cooling Te)
attains the setpoint value established (SetFC, parameterPS06).In order to avoid possible fluctuations of the enabling status of free-
cooling, it is also possible to set a differential (DiffFC, parameter PS07).
The condition of the step must last for at least a Minimum Enabling Time PS10 (default 30 seconds) before enabling/disabling free-
cooling.
In cases where the external probe is in error, free-cooling is disabled and the free-cooling control valve is deactivated.
In addition, the triggering of anti-frost resistance (and, even more so, the triggering of the corresponding alarm) will shut off the free-
cooling mechanism.
Other system safety mechanisms—failure of the regulating probe, failure of the anti-frost control probe, evaporator flow meter alarm,
circulation heat pump—cause the shutting down of the unit and thus the halting of the control of free-cooling.
8.15.2 Regulation of Free-Cooling
Enabling free-cooling allows you to activate control that is proportional to fan speed.
In cases where regulation of compressors, whether entering (lateral band) or leaving (neutral zone), the free-cooling setpoint always
corresponds to the regulation of the heat sinks.
SetFC-DiffFCSetFC
1
0 TInFC – Te
1 = F.C. On
0 = F.C. Off