Carel uChiller UCHBP00000200

72
ENG
µchiller +0300053EN rel. 2.2 - 14.12.2021
Functions
5.15.3 Water-cooled condensing unit
Free cooling is enabled based on the comparison between the user return water temperature and the source water temperature
(Temp. IN source); this controls modulation of the three-way valve that mixes the source water with the water returning from
the user terminals through the free cooling coil before entering the evaporator.
Free cooling capacity is controlled by modulating the three- way free cooling valve; in combined operation (free cooling + me-
chanical cooling), the three-way free cooling valve is always open at 100%.
Inputs used:
To enable free cooling:
• User return temperature;
• Source inlet temperature;
To manage capacity in free cooling mode:
• (according to the control probe used) Return/delivery water temp.
Outputs used:
• 0-10 V to manage the condenser fan
• 0-10 V to manage the free cooling valve.
300053_141_R01
E
L
F
S
CP
T
PU
M
T1
T2
M
C
FC_E
FC_V
V
V1
PS
T4
Fig. 5.x
Ref. Description Ref. Description
FC_E Free cooling heat exchanger V Solenoid valve
C Condenser FC_V Free cooling valve
E Evaporator PU User pump
F Filter-drier PS Source pump
L Liquid receiver T1 User return probe
CP Compressor T2 User delivery probe
FC_E Free cooling heat exchanger T4 Source return probe
S Liquid sightglass V1 Thermostatic expansion valve