CIAT DYNACIAT LG 080, Instruction Manual

Page: 57 / 68

14 - OPTIONS ET ACCESSORIES
14.2.4 - Operation of two units in master/slave
mode
The master/slave assembly is controlled on the water inlet pipes
(system return). All parameters, required for the master/slave
function must be configured using the Service Configuration
menu.
All remote controls of the master/slave assembly (start/stop, set
point, load shedding etc.) are controlled by the unit configured
as master and must only be applied to the master unit.
To permit master/slave operation both units must
be equipped with master/slave option.
Depending on the installation and control type, each unit can
control its own water pump.
Parallel or serial connection of two units
Water inlet control for hydraulic module
1 2
See legend in the next column.
Water outlet control
1 2
See legend in the next column.
Legend
B
Master unit
C
Slave unit
Control boxes of the master and slave units
Water inlet (for customers with both units)
Water outlet (for customers with both units)
Water pumps for each unit (included as standard for units with hydraulic
module)
●
Additional sensors for leaving water control, to be connected to channel 1
of the slave boards of each master and slave unit
IP communication BUS
Connection of two additional sensors
14.2.5 - LG unit operation with drycooler (specific
drycooler control option)
14.2.5.1 - Operating principle
The units have been designed to optimise the operation of
systems, using drycoolers as heat rejection systems.
With a variable-speed condenser water pump integrated into the
unit, the complexity of traditional systems using a 3-way valve
has been reduced.
The installation of an operational system is limited on the
condensing water loop side to connect the drycooler inlet and
the water outlet pipe on the unit.
Connect’Touch control of the units includes algorithms to permit
constant automatic optimisation of
- drycooler fan stage operation
- water flow rate variation in the loop between the condenser
and the drycooler.
Parallel control of the fan stages (up to 8 stages maximum) and
of the variable water flow rate of the loop permit year-round
system operation down to outside temperatures of -10°C without
any additional control.
14.2.5.2 - Communication to control the drycooler
The electronic board and LEN communication BUS, integrated
in the control box of the drycooler, via an option selected by the
manufacturer, are used for controlling the whole system.
The drycooler and the unit must be equipped with
the Drycooler Management option.
The option is provided in the manufacturer’s drycooler control
box. Connect the unit to board AUX1 in the drycooler, using a
communication cable. This cable must be connected to the 3
way Wago type plug (5 mm spacing or equivalent). The
communication cable should be a shielded type.
Connect’Touch optimises system operation to obtain the best
efficiency with variation of the water flow rate and the number of
fans required for any thermal load and outside temperature
conditions.
The electronic board (AUX1) integrated in the control box of the
drycooler has analogue inputs for outside air temperature and
drycooler outlet water temperature sensors, as well as eight
digital outputs permitting control of up to eight fan stages.
14.2.5.3 - Configuration of the number of fan stages and
the automatic changeover of the fan stages
Please refer to the instructions in the DYNACIAT LG/LGN
Connect’Touch control manual for the configuration of the number
of fan stages to be controlled. Simply enter the number of fan
stages of the drycooler in the Connect’Touch service menu. The
number of digital outputs controlling the fans are activated by
the control.
Connect’Touch controls the automatic switching of all fan stages,
based on the operating time and number of start-ups for each
of the stages. This function prevents fan motors from only running
a little or not at all and the shafts seizing up, especially during
periods with a low cooling demand, when the outside temperature
is low. Switching is often specified by the drycooler manufacturers
to ensure a long operating life of fan motors that are only used
a little or not at all in these particular operating conditions.
EN-57 Dynaciat LG/LGN