POWERCIAT LX ST/HE/XE
EN-
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10.1.2 - Communication to control the drycooler
When the option is selected, a specific electronic board is
integrated in the control box of the drycooler. A communication
LEN bus connected between the drycooler (board AUX1)
and the chiller is needed for the overall system control.
This cable should be a 3 points Wago type (5 mm spacing or
equivalent) and should be shielded.
The board integrated in the control box of the drycooler has
analogue inputs for outside air temperature and drycooler leaving
water temperature sensors, as well as digital outputs permitting
the control of the fans.
The option works as a system split in two parts:
The chiller (with free cooling option)
• Dedicated control algorithms with LEN connector to
communicate and control the drycooler
The drycooler (with free cooling option):
• AUX board with the I/O
• OAT sensor to be place in outdoor zone.
• Dry Cooler Leaving Water Temperature (factory mounted)
• Water loop Temperature (to be mounted on the common pipe
before valve)
• Control & 230V power supply for 2 two ways valve or one
three ways valve
The temperature difference between dry-cooler OAT and water
loop sensor defines if free cooling mode can be activated.
10.1.3 -
Configuration to control the fans
To set the configuration corresponding to the drycooler installed
(number of fans, control type – fixed or variable speed), please
refer to the instructions in the TouchPilot control IOM. Following
these parameters, the TouchPilot control will activate the adequate
number of digital outputs to control the fans.
TouchPilot controls the automatic switching of all fans, based on
operating time and number of start-up, to ensure a long operating
life of fan motors.
Compatible fans configuration:
-
1 to 20 fans,
-
fixed speed or variable speed,
-
1 or 2 rows of fans.
Refer to the drycooler electrical diagram to see the fan stages
arrangement.
10.1.4 - Valves on the water loop
The free cooling system requires 2 two-way valves (one Normally
Opened, one Normally Closed) or a three-way valve, not supplied
with the unit or the dry cooler.
A two-way valves kit is available in the list of drycooler
accessories.
The drycooler electrics box includes a 230 V power supply for
2 two-way valves.
Recommended motor valve (per default): 230V 3 points
Refer to the wiring diagram for the drycooler for wiring the valves
on the customer terminal strip.
10.1.5 - Recommendations for system installation
For physical properties, dimensions, performances: refer to the
drycooler documentation.
For electrical connections, refer to the wiring diagram provided
with the drycooler.
For software configuration information, refer to the control
documentation of the chiller.
For correct installation of the drycooler, follow the professional
guidelines for the following topics:
• sizing the water piping;
• pressure drops (verify that the operating pressure of the unit
pump is sufficient compared to the pipes and valves pressure
drops; check for all operating modes)
• maximum height for the drycooler (in relation to the unit safety
valve)
• suitable positioning of the temperature sensors: outdoor air
temperature and water loop temperature.
10 - OPERATION WITH A FREE COOLING DRYCOOLER
