EWWD120~540MBYNN
Packaged water-cooled water chillers
4PW22685-1
Operation manual
10
Adjusting the temperature setpoint
The unit provides definition and selection of four or two independent
temperature setpoints.
In cooling operation, two setpoints are reserved for inlet control, the
other two are reserved for outlet control.
■
: inlet water temperature of evaporator, setpoint 1,
■
: inlet water temperature of evaporator, setpoint 2.
■
: outlet water temperature of evaporator, setpoint 1,
■
: outlet water temperature of evaporator, setpoint 2.
In heating operation, two setpoints are reserved for inlet control.
■
: inlet water temperature of condenser, setpoint 1,
■
: inlet water temperature of condenser, setpoint 2.
In double thermostat operation, two setpoints are reserved for inlet
control of the evaporator and two others are reserved for inlet control
of the condenser.
■
: inlet water temperature of evaporator, setpoint 1,
■
: inlet water temperature of evaporator, setpoint 2.
■
: inlet water temperature of condenser, setpoint 1,
■
: inlet water temperature of condenser, setpoint 2.
The selection between setpoint 1 and 2 is done by a remote dual
setpoint switch (to be installed by the customer). The actual active
setpoint can be consulted in the readout menu.
If the manual control mode is selected (refer to
), none of the above-mentioned setpoints will be active.
To adjust a setpoint, proceed as follows:
1
Enter the setpoints menu. Refer to the chapter
If the user password is disabled for setpoint modifications (refer
to the
"User settings menu" on page 11
), the controller will
immediately enter the setpoints menu.
If the user password is enabled for setpoint modifications, enter
the correct code using the
h
and
g
keys (refer to the
). Press
q
to confirm the password
and to enter the setpoints menu.
2
Select the setpoint to be adjusted using the
q
key.
A setpoint is selected when the cursor is blinking behind the
setpoint's name.
The "
" sign indicates the actual active temperature setpoint.
3
Press the
h
and
g
keys to adjust the temperature setting.
The default, limit and step values for the cooling (evaporator)
and heating (condenser) temperature setpoints are:
4
Press
q
to save the adjusted temperature setpoint.
When the setting has been confirmed, the cursor switches to the
next setpoint. When the setting has been cancelled, the cursor
returns to the upper left corner of the screen.
5
To adjust other setpoints, repeat from instruction 2 onwards.
Resetting the unit
The units are equipped with three kinds of safety devices: unit
safeties, circuit safeties and network safeties.
When a unit safety occurs, all compressors are shut down. The
safeties menu will indicate which safety is activated. The
screen of the readout menu will indicate
for all circuits. The red LED inside the
p
key lights up and
the buzzer inside the controller is activated.
When a circuit safety occurs, the compressor of the corresponding
circuit is shut down. The
screen of the readout menu
will indicate
for the circuit concerned. The
red LED inside the
p
key lights up and the buzzer inside the
controller is activated.
When a network safety occurs in a DICN configuration, the slaves not
detected by the network will function as stand alone units.
■
If the master is not detected by the network, all units will work as
stand alone units.
■
If a slave unit can not be found by the network, the red light
inside the
p
key of the master lights up and the buzzer inside
the control is activated.
■
If the master can not be found by the network, the red light
inside the
p
key of all the slaves light up and the buzzer inside
their controls are activated.
If the unit has been shut down due to a power failure, it will carry out
an autoreset and restart automatically when the electrical power is
restored.
To reset the unit, proceed as follows:
1
Press the
p
key to acknowledge the alarm.
The buzzer is deactivated.
The controller automatically switches to the corresponding
screen of the safeties menu: unit safety or circuit safety.
2
Find the cause of shutdown and correct.
Refer to
"Listing activated safeties and checking the unit status"
.
When a safety can be reset, the LED under the
p
key starts
blinking.
3
Press the
p
key to reset the safeties that are no longer active.
If required, enter the
or the
. (Refer to the installation manual “Setting the
password for safety reset”.)
Once all safety devices are disactivated and reset, the LED
under the
p
key goes out. If one of the safeties is still active, the
LED under the
p
key goes on again. In this case, return to
instruction 2.
4
It will only be necessary to switch the
o
key on again if a unit
safety occurs.
NOTE
The customer is also allowed to define a setpoint in
function of an analog input.
NOTE
Refer to “Customization in the service menu” chapter
“Setting of the changeable inputs and outputs” in the
installation manual
default value
!
"!
#$!
limit values
(a)
(a) For glycol units the lower limit of the cooling temperature
setpoint can be adapted in the factory. The following
values apply:
: 5°C, 3°C, –2°C, –7°C
: 2°C, 0°C, –5°C, –10°C
"
-->
#!
%
-->
&!
'
-->
'$!
step value
$!
$!
$!
NOTE
When a setpoint on a unit in a DICN system is set, this
setpoint will be transferred to all other units.
NOTE
Also consult
"Defining the schedule timer" on page 14
and
"Defining the display settings" on page 14
NOTE
To be able to reset the
circuit error
several precautions have to be taken. Refer to
“Resetting the
alarm” in the
installation manual.
If the user shuts down the power supply in order to repair a
safety, the safety will automatically be reset after power-up.
NOTE
The history information, i.e. the number of times a unit
safety or a circuit safety occurred and the unit status at
the moment of shutdown, can be checked by means of
the history menu.
