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On
Off
Normal operation
1. The pump is running.
– Normal operational
state.
On Off
2. The pump is not running.
Operational stop which
may be caused by
– the flow switch
connected
– the pump stop function.
a) The flow switch is closed.
The connection of a flow switch depends on the MGE functional
modules. See the wiring diagrams in figs
8
to
11
.
Is there 5 VDC across terminals 1-9?
(If an extended I/O module is installed, the flow switch may be
connected to DI3 (terminals 9-10) or DI4 (terminals 9-11)).
NO:
YES:
Flow switch closed = Pump is not supposed to run.
Flow switch open = Pump must be running.
If the flow switch is defective, replace it.
Does the pump start when the connection between the flow switch
terminals is cut?
NO:
YES:
Replace the I/O module.
The digital input is OK.
The flow switch is defective. Replace it.
b) The stop function has stopped the pump.
Does the pump start when you increase the flow and/or reduce the
pressure in the system?
NO:
YES:
If the sensor is OK, replace the terminal box.
The input is OK.
[To be continued on the next page]
Indicator lights
Condition/cause
Remedy
Green
Red
