Grundfos MAGNA3 D Installation And Operating Instructions Manual page 36

8.11.2 Relay outputs
See fig. 40, pos. 1.
The pump has two signal relays with a potential-free changeover
contact for external fault indication.
You can set the function of the signal relay to "Alarm", "Ready" or
"Operation" on the operating panel or with Grundfos GO.
The relays can be used for outputs up to 250 V and 2 A.
Warnings do not activate the alarm relay.
Use C and NC for fault signals as this enables serial
connections of more relays and detection of signal
cable defects.
Relay 1
NC NO C
Operation
Fig. 46 Relay output
Contact symbol
NC
NO
C
36
Relay 2
NC NO C
Alarm
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
unable to run.
1 2 3
1 NC NO C 2 3
NC NO C
• The power supply has been switched off.
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 power supply has been switched off.
1 2 3
1 NC NO C 2 3
NC NO C
Activated:
• The pump is running.
1 2 3
NC NO C
Factory settings of relays:
Relay
1
2
Relay output in twin-head pumps
The relay output for both the "Alarm", "Ready" and "Operation"
functions operates independently on each pump head. If, for
example, a fault occurs in one of the pumps, its respective relay
is triggered.
Function
Operating signal
Alarm signal