Operation manual
13
EWAD120~340MBYNN
Packaged air-cooled water chillers
4PW22683-1
•
: The unit is considered as a
unit and its
function is then also simular to a unit defined as
, but this
unit however, will only come into operation if:
another unit is in alarm
another unit is in
mode
the setpoint is not reached when all other units have been
running on full capacity for some time
If more than one unit is defined as
, only 1 of the units
will be really standby. The unit which is really standby will be
decided by the number of running hours.
•
: Putting this unit ON or OFF will not put
other units ON or OFF.
on such a unit is
possible.
If the unit is put to
, and the unit is ON, it
will be controlled by the DICN network as a
unit.
■
: The
time defines the target difference in
running hours between one unit and another unit with
%%%% 5
. This value is important for maintenance
purposes. The difference in setting among different units should
be high enough as to avoid servicing of the units all at the same
time. The lower and upper limits are 0 and 9000 hours
respectively. The default value is 0 hours.
■
: Set if the pump must operate as long as the chiller
is on (
), or during compressor on condition only (
).
When
is selected, the voltage free contact S9L will
remain closed as long as the chiller is on. When
is
selected, the voltage free contact S9L will remain closed as long
as the compressor is on.
Also refer to the separate manual "Installation examples for a
DICN configuration".
Activating or deactivating the setpoints password
The
screen of the user settings menu allows
the user to activate or deactivate the user password needed to
change the temperature setpoint. When deactivated, the user does
not have to enter the password each time he wants to change the
setpoint.
Defining BMS control
allows the user to control the unit from a supervisory system.
The
screen and
screen of the
service menu have to be used to set BMS parameters. Refer to
“Customization in the service menu” chapter “Defining the BMS
settings” in the installation manual.
Tasks of the timers menu
Checking the actual value of the software timers
As a protective measure and to ensure correct operation, the
controller's software features several countdown timers:
■
LOADUP (
– refer to the thermostat parameters): starts
counting when a thermostat step change has occurred. During
the countdown, the unit is not able to enter a higher thermostat
step.
■
LOADDOWN (
– refer to the thermostat parameters): starts
counting when a thermostat step change has occurred. During
the countdown, the unit will not be able to go to a lower thermo-
stat step.
■
FLOWSTART (
– 15 sec): counts down when the
waterflow through the evaporator is continuous and the unit is in
standby. During the countdown, the unit cannot start up.
■
FLOWSTOP (
– 5 sec): starts counting when the
waterflow through the evaporator stops after the flowstart timer
has reached zero. If the waterflow has not restarted during the
countdown, the unit will shut down.
■
PUMPLEAD (
– refer to the pump control settings):
starts counting whenever the unit is switched on. During the
countdown, the unit cannot start up.
■
PUMPLAG (
– refer to the pump control settings):
starts counting whenever the unit is switched off. During the
countdown, the pump keeps running.
■
STARTTIMER (
&
– 10 sec): starts counting
whenever a compressor starts up. During the countdown, no
other compressor can start up.
■
GUARDTIMER (
/
– 60 sec): starts counting when the
compressor (circuit 1/2) has been shut down. During the
countdown, the compressor cannot be restarted.
■
ANTIRECYCLING (
/
– 600 sec): starts counting when
the compressor (circuit 1/2) has started. During the countdown,
the compressor cannot be restarted.
■
STARTUPTIMER (
/
– 180 sec): starts counting
when the compressor (circuit 1/2) has started. During the
countdown, the compressor is limited to a maximum
capacitystep of 30%.
To check the actual value of the software timers, proceed as follows:
1
Enter the
. (Refer to the chapter
The controller displays the actual value of the
: the loadup timer, the loaddown timer, the flowstart
timer, the flowstop timer (when the unit is on and the flowstart
timer has reached zero), the pumplead timer and the pumplag
timer.
2
Press the
h
key to check the compressor timers.
The controller shows the actual value of the
: the guard timers (one per circuit) and the antirecycling
timers (one per circuit).
3
Press the
h
key to check the remaining timers.
The controller shows the actual value of the
.
NOTE
Put a unit to
when servicing the
machine. In this case it is possible to switch ON or
OFF this unit without switching ON or OFF the other
units of the network.
It is also possible then to operate the unit in
.
Put a unit to
continuously if the
operator wants to decide by himself when this unit
must operate.
Note that in this case, it makes no sense to define
another unit of the network as
. Since there is
a unit set continuously to
, the
unit will continuously be considered as a
unit.
NOTE
The settings on this screen of the network menu must
be executed for all chillers connected to the system.
NOTE
If changed on one of the units in a DICN configuration,
this setting is automatically transferred to all the other
units in the network.
