Faults; Fault: The Unit Runs But Does Not Pump; Fault: The Unit Does Not Run Smoothly And Is Noisy - Wilo SUB TWU 3 Notice De Montage Et De Mise En Service

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overload: Is displayed if the current consumption
5.
exceeds the set value "Imax" in the operating pa-
rameters. This can be caused by difficult operat-
ing conditions, frequent restarts or a faulty motor.
Check before resetting the error:
• Does the set value "Imax" match the informa-
tion on the name plate?
• Is the system working in the permitted usage
conditions?
If you have checked both of the above and the
error persists, consult Wilo customer service.

9.2. Faults

9.2.1. Fault: The unit does not start or only after
a delay
1. Electricity supply interrupted, short circuit
or earth fault in the cable or motor windings
• Have the motor and wires checked by a spe-
cialist and replaced if necessary Check the error
messages on the frequency converter
2. Fuses, the motor protection switch and/or
monitoring devices are triggered
• Have a specialist inspect the connections and
correct them as necessary
• Have the motor protection switches and fuses
installed or adjusted according to the technical
specifications, and reset monitoring equipment
• Check that the impeller runs smoothly. Clean or
free it as necessary
3. Pressure difference between Pmax and Pmin is
too small
• Adapt the value "Delta P" in the operating
parameters
4. Too little water consumption
• Water removal is not noticed, installation
of an expansion tank with 1-2 l volume
9.2.2. Fault: The unit starts, but the motor protection
switch triggers shortly after start-up
1. The thermal trigger on the motor protection
switch is incorrect / set incorrectly
• Have a specialist compare the selection and
setting of the trigger with the technical specifi-
cations and correct if necessary
2. Increased power consumption due to major
voltage drop
• Have an electrician check the voltage on each
phase and rewire if necessary
3. Incorrect direction of rotation
• Change the direction of rotation using the
menu.
4. Impeller impeded by adhesive material,
b lockages and/or solid matter, increased
c urrent consumption
• Switch off the unit, secure it against being
switched on again and free the impeller or clean
the intake port
5. The pumped liquid is too dense
• Contact the manufacturer

9.2.3. Fault: The unit runs but does not pump

1. The display shows the error "Dry operation"
48
TROUBLESHOOTING AND POSSIBLE SOLUTIONS
• No pumped liquid: Check the intake and open
the slider if necessary
• Clean the intake, slider, intake port or intake
strainer
• The discharge pipe empties during idle times;
check the pipework for leaks and the check
valve for dirt; rectify the error
2. Impeller blocked or obstructed
• Switch off the unit, secure it against being
switched on again and free the impeller
3. Defective pipeline
• Replace defective parts
4. Intermittent operation (cycles)
• Check the control panel
9.2.4. Fault: The unit runs, but not at the stated
operating levels
1. Intake blocked
• Clean the intake, slider, intake port or intake
strainer
2. Impeller blocked or obstructed
• Switch off the unit, secure it against being
switched on again and free the impeller
3. Incorrect direction of rotation
• Change the direction of rotation using the
menu.
4. Air in the system
• Bleed the system
5. Defective pipeline
• Replace defective parts
6. Inadmissible levels of gas in the pumped liquid
• Contact the manufacturer
7. Excessive decrease in the water table during
operation
• Check the supply and capacity of the system
8. Value "Pmax" set too high
• Adapt the value "Pmax" according to the pump
curve or fit a unit with greater output
9.2.5. Fault: The unit does not run smoothly
and is noisy
1. Unit is operating in an inadmissible range
• Check the operational data of the unit and
correct if necessary, and/or adjust the operating
conditions
2. The intake port, strainer and/or impeller is
blocked
• Clean the intake port, strainer and/or impeller
3. The impeller is obstructed
• Switch off the unit, secure it against being
switched on again and free the impeller
4. Inadmissible levels of gas in the pumped liquid
• Contact the manufacturer
5. Incorrect direction of rotation
• Change the direction of rotation using the
menu.
6. Signs of wear
• Replace worn parts
7. Defective motor bearing
• Contact the manufacturer
8. The unit is installed under mechanical strain
• Check the installation, use rubber spacers
if necessary
WILO SE 12/2012 Ed.03 DIN A4