7
3.6 - Actuators
Electronic Expansion Valve
The electronic expansion valve (EXV) is used to adjust the
refrigerant.flow.to.changes.in.the.operating.conditions.of.the.
machine. The high degree of accuracy with which the piston
is.positioned.provides.precise.control.of.the.refrigerant.flow.
and suction superheat.
Flow switch
For.units.without.internal.pumps,.a.flow.switch.is.mounted.
to.ensure.that.the.minimum.flow.rate.required.for.the.correct.
operation and protection of the system is maintained. If the
flow.switch.fails,.the.alarm.condition.shuts.off.the.unit.
Water pumps (optional)
The controller can independently regulate each water heat
exchanger.pump..Touch.Pilot.Junior.enables.constant.flow.
control based on the minimum pump speed setpoint.
Water.flow.control.can.also.be.based.on.the.heat.exchanger.
temperature difference or the water pressure difference.
Boiler
If there is a unit fault in the heating mode this output authorises
start-up and shutdown of a boiler. 30WG/30WGA units can
be.fitted.with.a.boiler.which.is.energised.only.when.requested.
by the controller in case of heating demand
.
For 61WG units,
the boiler is activated when the operating conditions are not
suitable for thermodynamic heating or the unit is down due
to a detected failure. See also section 8.10.1.
Electric heaters
Electric heaters are used as a supplementary heating source
in the heating mode. See also section 8.10.2
.
3.7 - Available connections
Connections available at the user terminal block may vary
depending on the selected options. The following table
summarizes connections at the user terminal block.
IMPORTANT:
Some contacts can be accessed only when
the unit operates in Remote mode.
3.7.1 - Terminal block connections
Description
Board
Connector Remarks
Remote On/Off
contact
SIOB,
cir A
+:32/ -:33
Used for the unit on/off
control (Remote mode)
Remote Heat/
Cool contact
SIOB,
cir A
+:63/ -:64
Used to set cooling and
heating when the unit is in
Remote mode
Switch-
controlled
demand limit
SIOB,
cir A
+:73/ -:74
Used to control demand
limit
Switch dual
setpoint
SIOB,
cir A
+:65/ -:66
Used to select the second
cooling setpoint
Lock switch
SIOB,
cir A
+:34/ -:35
Used for the customer
safety loops
Condenser
3-way valve
SIOB,
cir A
+:80+/-:80- Used to control the water
flow on the condenser side
Boiler
SIOB,
cir A
+:69/ -:70
Used to command a boiler
Running
SIOB,
cir A
+:37/-: 38
Used to signal a running
status (at least one
compressor start)
Description
(cont.)
Board
(cont.)
Connector
(cont.)
Remarks
(continued)
Alarm
SIOB,
cir A
+: 30/-: 31 Used to signal an alarm
Domestic hot
water (DHW)
AUX1
-:310 /
CH12: 311
Used to control domestic
hot water production
Domestic hot
water (DHW)
priority switch
AUX1
-:312 /
+:313
Used to control domestic
hot water priority
Summer
switch
AUX1
-:323 /
+:322
Used to stop the Space
Heating loop additional
pump during summer time
Electrical
Heater Stage 1
AUX1
341 / 12
Used to control the
electrical heater stage 1
Electrical
Heater Stage 2
AUX1
342 / 12
Used to control the
electrical heater stage 2
Electrical
Heater Stage 3
AUX1
343 / 12
Used to control the
electrical heater stage 3
Electrical
Heater Stage 4
AUX1
344 / 12
Used to control the
electrical heater stage 4
Additional
pump
command
AUX1
365 / 12
Used to command the
additional pump in case of
DHW option
DHW
diverting valve
AUX1
340 / 12
Used to command the DHW
loop in case of DHW option
3.7.2 - Volt-free contact (on/off and cooling/heating)
For units with a boiler, on/off contacts and cooling/heating
contacts are as follows:
Off
Cooling
Heating
On/Off contact
open
closed
closed
Cooling/Heating contact
open
open
closed
Off:
Unit is stopped
Cooling: Unit is allowed to start in Cooling
Heating: Unit is allowed to start in Heating
3.7.3 - Volt-free setpoint selection contact
When the unit is under remote control, the volt-free contact
is used to determine the active setpoint. This dry contact is
used to switch between setpoints. It is active only when the
control is in Remote mode. See also section 8.5.1.
Contact
Active setpoint
SP1
SP2
SP3
Auto
SETP_SW1
open
close
open
close
SETP_SW2
open
open
close
close
3.7.4 - Volt-free demand limit selection contact
One dry contact can be used to limit unit capacity. The limit
threshold.can.be.defined.via.the.user.interface.in.the.Setpoint.
100%
Limit 1
Limit 2
Limit 3
Demand limit 1 contact
open
closed
open
closed
3.7.5 - Summer switch (HDC option)
For units with HDC option, the summer switch can be used
to control with the volt-free contact.
Summer switch
Summer mode
open
not active
closed
active
