AQUACIAT
POWER
EN -
8
4.6 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.
Water 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.
The minimum flow rate threshold depends on the unit size and
is configured automatically at the start-up. If the flow switch
fails, the alarm condition shuts off the unit.
Water heat exchanger pumps (optional)
The controller can regulate one or two fixed speed or variable
speed water heat exchanger pumps and takes care of the
automatic changeover between these pumps.
Four-way valve (heat pumps)
The control actuates the four-way valve for cooling / heating
mode and defrosts' sessions.
4.7
Terminal block 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.
Terminal block connections
Description
Board
Input/Output
Connector
Remarks
On/Off switch
SIOB, circuit A
DI-01
J1
Used for the unit On/Off control (Remote mode)
Heat/Cool switch
SIOB, circuit A
DI-04
J1
Used to switch between cooling and heating when the unit is in
Remote mode (Heat pumps only)
Second setpoint switch
SIOB, circuit A
DI-02
J1
Used to switch between setpoints
Demand limit switch 1
SIOB, circuit A
DI-03
J1
Used to control demand limit
Alarm relay
SIOB, circuit A
DO-05
J23
Indicates alarms
Running relay
SIOB, circuit A
DO-06
J22
Indicates if the unit is ready to start or operating
Desuperheater demand
SIOB, circuit B
DI-04
J1
Heat recovery is allowed
Lock switch
SIOB, circuit B
DI-02
J1
Used for the customer safety loops
Customer pump 1
SIOB, circuit B
DO-05
J23
The control can regulate one or two evaporator pumps and
automatically change over between the two pumps
Customer pump 2
SIOB, circuit B
DO-06
J22
The control can regulate one or two evaporator pumps and
automatically change over between the two pumps
Optional
Setpoint reset control
SIOB, circuit A
AI-10
J9
Allows the user to reset the currently selected setpoint
Occupancy override
SIOB, EMM
DI-01
J1
Used to switch between occupied (closed contact) and unoccupied
mode (open contact)
Demand limit switch 2
SIOB, EMM
DI-02
J1
Used to control demand limit
Customer interlock
SIOB, EMM
DI-03
J1
Used for the customer safety loops
Ice done contact
SIOB, EMM
DI-04
J1
Used to control the setpoint for ice storage in unoccupied mode
Capacity limit control
SIOB, EMM
AI-10
J9
Used for capacity limitation
Chiller partially shutdown
SIOB, EMM
DO-05
J23
Indicates the shutdown of one of the circuits
Chiller totally shutdown
SIOB, EMM
DO-06
J22
Indicates the unit shutdown
Chiller capacity running output
(0 to 10 V)
SIOB, EMM
AO-01
J10
R eports the capacity percentage of the unit
Desuperheater customer pump
SIOB, EMM
DO-01
J2
The control can regulate a customer pump for heat recovery.
The connection has to be done between the pin DO-01 of connector
J2 and the pin IN-01 of connector J4
IN-01
J4
4 - HARDWARE