Input/Output Communication - Grundfos MAGNA3 Installation And Operating Instructions Manual

5.5 Input/output communication

• Relay outputs
Alarm, ready and operating indication via signal relay.
• Digital input
– Start/Stop (S/S)
– Min. curve (MI)
– Max. curve (MA).
• Analog input
0-10 V or 4-20 mA control signal.
To be used for external control of the pump or as sensor input
for the control of the external setpoint.
The 24 V supply from pump to sensor is optional and is
normally used when an external supply is not available.
5.5.1 Relay outputs
See fig. 12, pos. 1.
The pump incorporates two signal relays with a potential-free
changeover contact for external fault indication.
The function of the signal relay can be set to "Alarm", "Ready" or
"Operation" on the pump control panel or with the Grundfos GO
Remote.
The relays can be used for outputs up to 250 V and 2 A.
Relay 1
NC NO C
Alarm
Fig. 13 Relay output
Contact symbol
NC
NO
C
Relay 2
NC NO C
Operation
Function
Normally closed
Normally open
Common
The functions of the signal relays appear from the table below:
Signal relay Alarm signal
Not activated:
• The power supply has been switched off.
1 2 3
NC NO C
1 2 3
• The pump has not registered a fault.
NC NO C
Activated:
• The pump has registered a fault.
1 2 3
NC NO C
Signal relay Ready signal
Not activated:
• The pump has registered a fault and is
1 2 3
1 NC NO C 2 3 unable to run.
NC NO C
Activated:
• The pump has been set to stop, but is ready
to run.
1 2 3
NC NO C
• The pump is running.
Signal relay Operating signal
Not activated:
• The pump is not running.
1 2 3
1 NC NO C 2 3
NC NO C
Activated:
• The pump is running.
1 2 3
NC NO C
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