Grundfos MAGNA3 D Installation And Operating Instructions Manual page 37

8.11.3 Digital inputs
See fig. 40, pos. 2.
You can use the digital input for external control of start-stop or
forced maximum or minimum curve.
If no external on-off switch is connected, the jumper between
terminals start-stop (S/S) and frame ( ) must be maintained. This
connection is the factory setting.
M M
A I
Start-stop
Fig. 47 Digital input
Contact symbol
M
A
M
I
S/S
External start-stop
You can start and stop the pump via the digital input.
Start-stop
S/S
H
S/S
H
S/S
On-off timer
Function
Maximum curve
100 % speed
Minimum curve
Start-stop
Frame connection
Normal duty
Factory setting with jumper
between start-stop and
Q
Stop
Q
Externally forced maximum or minimum curve
You can force the pump to operate on the maximum or minimum
curve via the digital input.
M
H
A
M
H
A
M H
I
M
H
I
Select the function of the digital input on the pump operating
panel or with Grundfos GO.
Digital input on twin-head pumps
The Start/Stop input operates on system level, meaning that if the
master pump head receives a stop signal, the system stops.
As a main rule, the digital input is only effective on the master,
which is why it is important to know which pump is assigned as
master, see fig. 48.
XXXXXXXXXXXXXXXXXXXXXXXX
P/N: XXXXXXXX
S/N: XXXXXXXX
PC: XXXX
Model: X
I is defined as master.
Fig. 48 Identifying the master pump head on the nameplate
For redundancy purposes, the digital input can be used
concurrently on the slave pump head. However, as long as the
master is powered up, the input on the slave will be ignored. In
the event of power loss on the master, the digital input of the
slave will take over. When the master pump head is back on, the
master takes over and controls the system.
.
Maximum curve
Normal duty
Q
Maximum curve
Q
Minimum curve
Normal duty
Q
Minimum curve
Q
I [A] P [W]
1 1
XXXX
XXXX
Assembled In USA
37