Grundfos MAGNA3 25-80 Installation And Operating Instructions Manual page 32

7.9.4 Analog input
The pump has an analog input for the connection of an external
sensor for measuring temperature or pressure. See section
3.9 Wiring diagrams.
You can use sensor types with 0-10 V or 4-20 mA signal.
You can also use the analog input for an external signal for the
control from a building management system or similar control
system. See fig. 51.
• When the input is used for the heat energy monitor, install a
temperature sensor in the return pipe.
• If the pump is installed in the return pipe of the system, install
the sensor in the flow pipe.
• If the constant-temperature control mode has been enabled
and the pump is installed in the flow pipe of the system, install
the sensor in the return pipe.
• If the pump is installed in the return pipe of the system, you
can use the internal temperature sensor.
You can change the sensor type, 0-10 V or 4-20 mA, on the
operating panel or with Grundfos GO.
24V
24V
Vcc Vcc
sensor sensor
Fig. 48 Analog input for external sensor, 0-10 V
24V
Vcc
sensor
Fig. 49 Analog input for external sensor, 4-20 mA
In order to optimise the pump performance, you can use external
sensors in the following cases:
Function or control mode
Heat energy monitor
Constant temperature
Proportional pressure
32
N
N
signal signal
N
I
signal
Sensor type
Temperature sensor
Temperature sensor
Pressure sensor
24V IN
Vcc
Signal
Fig. 50 Examples of external sensors
Pos. Sensor type
Combined temperature and pressure sensor,
1 Grundfos type RPI T2.
1/2" connection and 4-20 mA signal.
Pressure sensor, Grundfos type RPI.
2
1/2" connection and 4-20 mA signal.
For further details, see section
24V
Fig. 51 Examples of external signal for the control via BMS or
PLC
Analog input on twin-head pumps
For redundancy purposes, the analog input can be used
concurrently on the slave pump head. As long as the master is
powered up, the input on the slave will be ignored. However, in
the event of power loss on the master, the analog input of the
slave will take over. When the master pump head is back on, the
master takes over and controls the system.
1
2
11.4 External sensors.
BMS
PLC