EWWD120~540MBYNN
Packaged water-cooled water chillers
4PW22685-1
Operation manual
14
Defining the thermostat settings
When automatic control mode is selected, the unit uses a thermostat
to control the cooling or heating capacity. However, the thermostat
parameters are not fixed and can be modified via the
screen of the user settings menu.
The default, limit and step values for the thermostat parameters are
shown in
Defining the lead-lag mode
(only for EWWD360~540)
The lead/lag mode determines which of both circuits starts up first in
case of a capacity demand.
The lead-lag parameters are:
■
Automatic: the controller decides whether circuit 1 or circuit 2
starts up first.
Manual C1>C2: circuit 1 starts up before circuit 2. If circuit 1 is
deactivated due to a failure, circuit 2 will start up instead.
Manual C2>C1: circuit 2 starts up before circuit 1. If circuit 2 is
deactivated due to a failure, circuit 1 will start up instead.
■
: In the automatic mode, the number of hours
indicated on the display is the maximum difference between the
running hours of both circuits. This value is important for main-
tenance purposes. It should be set high enough so that both
circuits do not require maintenance at the same time and that at
least one circuit can remain constantly active.
The lower and upper limits are 100 and 1000 hours respectively.
The default value is 1000 hours.
■
4
: If this parameter is set on
(Yes), both circuits
will try to go up in capacity alternatingly.
If this parameter is set on
(No), the leading circuit will try to go
to full capacity before the lagging circuit can startup.
Defining the capacity limitation settings
In the
screen up to four possible capacity
limitation settings can be configured.
A capacity limitation can be activated:
■
:
•
see
"Defining the schedule timer" on
•
when a changeable input is configured as
capacity limitation.
•
: to activate capacity limitation 1.
•
: the capacity limitation is not active.
■
# %
: capacity limitation value of circuit 1 in
case of capacity limitation 1/2/3/4.
Defining the pump control settings
The
screen of the user settings menu allows the user
to define the pump-leadtime and pump-lagtime.
■
: used to define the time that the pump must run
before the unit (or the compressor in case
is selected in a DICN configuration) can start up.
■
: used to define the time that the pump keeps
running after the unit (or the compressor in case
is selected in a DICN configuration) has been
stopped.
Defining the schedule timer
To activate the screens of the schedule timer or holiday period, these
first need to be enabled by changing their setting to
in the
appropriate screen. To de-activate the schedule timer or holiday
period, their setting needs to be reset to
. (See
The
screen of the user settings menu allows the
user to define the schedule timer settings.
Each day of the week can be appointed to a group. The actions
defined in a group will be executed in each day belonging to that
group.
■
,
,
,
,
,
and
: used to define to which
group each day of the week belongs (
/
/
/
#
/
%
).
■
For each of the four groups up to nine actions can be set, each
with their respective timing. Actions include: putting the unit on
(
), putting the unit off (
), setting a setpoint (
,
,
,
) and setting capacity limitation (
,
,
#
,
%
,
).
■
Beside these four groups there is also a holiday period group
which is set the same way as the other groups. Up to 12 holiday
periods can be entered in the
screen. During these
periods the schedule timer will follow the settings of the holiday
period group.
Defining dual evaporator pump control
The
screen of the user settings menu allows the
user to define the steering of two evaporator pumps (for this to be
possible a changeable digital output has to be configured for a
second evaporator pump in the service menu). Refer to the
installation manual.
■
: used to define which kind of control will be used for the
two evaporator pumps. When automatic rotation is chosen the
offset on running hours also has to be entered.
•
: pump 1 and pump 2 will alternate to the offset on RH.
•
: pump 1 will always start up first.
•
: pump 2 will always start up first.
■
: used to define the offset in running hours
between the two pumps. Used to switch over between pumps
when they work in automatic rotation mode.
Defining the display settings
The
screens of the usersettings menu allows
the user to define the choice of language, time and date.
■
: used to define the language of the displayed
information of the controller (on the first screen). (Push the
q
button repeatedly to change the operating language).
■
: used to define the present time (on the second screen).
■
: used to define the present date (on the second screen).
NOTE
■
If changed on one of the units in a DICN
configuration, this setting is transferred to all other
units in the network.
■
A functional diagram showing the thermostat
parameters can be found in
NOTE
Refer to “Customization in the service menu”,
chapter “Setting of the changeable digital inputs
and outputs” in the installation manual
NOTE
A functional diagram showing the schedule timer
working can be found in
NOTE
The unit always works with “last command”. This means
that the last command given, whether manually by the
user or by the schedule timer, is always executed.
Examples of command that can be given are switching
the unit on/off or changing a setpoint.
NOTE
In case of a DICN network, defining the schedule timer
will only be possible through the master unit. In case of
power failure of the master unit, the slave units
however, will still operate according to settings of the
schedule timer.
