Wilo SiFire Easy Série Notice De Montage Et De Mise En Service page 74

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Faults
Motor fails to reach nominal speed
Non-operating pumps suddenly started Incorrect sizing of power line
Presence of voltage on motor housing
Unusual overheating of the exterior of
motor
Main pump starts before jockey pump
Main pump starts immediately with
inhibition indicator in position 1
Sudden speed drop
Magnetic noise
Sudden whistling
Mechanical noise
Overheating of pump/motor bearings
Unusual vibrations
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Causes
Voltage at motor terminals too low
False contacts in the power contactor or
problems with the start device
Phase failure
False contacts in power supply cables
Winding to the earth or short-circuit
Insufficient voltage
Pump sizing
Contact between line cables and earth
Humid or old insulation
Short-circuit between terminals and
external housing
Pump overload
Coupling out of axis
Ambient temperature beyond 40 °C
Voltage higher/lower than nominal value
Phase failure
Insufficient ventilation
Sliding between stator and rotor
Unbalanced voltage on three phases
Pressure switch on the main pump is cal-
ibrated at a higher value than the jockey
pump
Pressure switch calibrated at a lower
value than the system pressure
Water level in the priming tank is too low
Instantaneous overload/foreign part in
pump
Single-phase operation
Voltage drop
Motor winding or short-circuit
Friction between stator and rotor
Loosened screws
Loosened screws in the fan cover cap/
coupling cover cap
Sliding between fan and motor, and
between coupling and coupling cover
cap etc.
Foreign parts in motor or pump
Not aligned coupling
Bearings insufficiently lubricated/worn
out/broken
Bearings are damaged
Insufficient lubrication
Pump and motor are not aligned
No vibration-damping sleeve devices on
the unit
Pump cavitation
Too much air in the water
Bearings, pump/motor shaft are worn out Replace
Pump/motor coupling is worn out
Pump and motor are not aligned
Remedies
Check power supply voltage, connec-
tions and the cross-section of the cables
in the power line.
Check and repair
Check line, connection and fuses
Check terminal fixing
Dismantle the motor, repair or replace it
Check and replace
Check power supply
Remove the rotating parts then check
Correct connections
Wipe motor or re-wind it.
Check insulation between terminals and
housing.
Dismantle and check
Align correctly
Ventilate the space
Check up stream power supply
Check power supply and fuses
Check strainers and pipes. Resize
Repair or replace the motor
Check power supply
Check pressure switch settings
Check pressure switch settings
Increase the pressure level in the installa-
tion
Check level of priming tank
Dismantle pump
Check supply and fuses
Check supply
Dismantle the motor, then repair or
replace it.
Dismantle the motor, then repair or
replace it.
Check and tighten
Check and tighten
Guarantee the correct distance and re-
assemble.
Dismantle and remove
Re-align
Lubricate or replace
Replace
Lubricate again
Re-align
Install or repair
Review the dimensioning of installation
Make sure that there are no leaks in the
suction line. Check the distance between
the suction points if several pumps are
installed. Fit anti-vortex plates
Replace
Re-align
WILO SE 01/2018