Carel MuChiller UCHBD00001130, User Manual

Page: 68 / 108

ENG
Fig.5.u
Ref. Description
FC_E Free cooling heat exchanger
C Condenser
E Evaporator
F Filter-drier
L Liquid receiver
CP Compressor
S Liquid sightglass
Ref. Description
FC_V Free cooling valve
PU User pump
T1 User return probe
T2 User delivery probe
T3 Outside temperature probe
V1 Thermostatic expansion valve
V Solenoid valve
Tab.5.e
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 c mechanical cooling), the three-way free cooling valve is always open at 100%.
Inputs used:
To enable free cooling:
o
User return temperature;
o
Source inlet temperature;
To manage capacity in free cooling mode:
o
(according to the control probe used) Return/delivery water temp.
Outputs used:
o
0-10 V to manage the condenser fan
o
0-10 V to manage the free cooling valve.
68 | 5. Functions
µC0300053EN rel. 1.0 – 23.07.2018