En
gl
is
h (
G
B)
28
9. Faults
In the event of faults, a warning or an alarm is
triggered. Active faults are indicated by the LEDs.
In case of a warning the pump continues running.
In case of an alarm the pump stops dosing.
For some alarms the pump tries to restart
periodically. To initiate a restart attempt manually, set
the adjusting knob to 0 % for 2 seconds. When the
cause of the alarm has been remedied, the pump
starts automatically and switches back to normal
operation.
9.1 Indicated faults for DDE-B
❍
= LED flashing
empty table cell = LED off
*
For some alarms the pump tries to restart periodically.
CAUTION
Automatic startup
Minor or moderate personal injury
- Before remedying the cause of the fault,
make sure the pump is ready to be
started.
- Before starting work on the pump, the
pump must be disconnected from the
power supply. The system must be
pressureless.
LED status
Pump status Fault
Possible cause
Possible remedy
❍
Standby*
Motor blocked
(Alarm)
• Backpressure greater than
nominal pressure
• Reduce backpressure.
Observe section
.
• Incorrectly installed
diaphragm
• Install the diaphragm
correctly.
• Damage to gears
• Hall sensor failure
• Motor failure
• Contact your Grundfos
service partner.
• Leaky/dirty outlet valve.
Dosing medium flows back
from the outlet line into the
dosing head and moves
the motor.
• Inlet pressure too high.
Dosing medium flows from
the inlet line into the
dosing head and moves
the motor.
• Replace valve if
necessary. See section
• Install screen in inlet line.
• Reduce inlet pressure.
Observe section
.
Cavitation
(Alarm)
• Blocked / constricted /
squeezed inlet line
• Blocked/constricted inlet
valve
• Suction lift too high
• Viscosity too high
• Cavitation moves the
motor
• Reduce suction lift.
• Increase inlet line
diameter.
• Check inlet line and open
isolating valve if
necessary.
Motor
overheated
(Alarm)
• Ambient temperature to
high
• Reduce ambient
temperature.
• Stop pump until motor
cools down.
