Wilo -SiFire FIRST Installation And Operating Instructions Manual page 79

FAULT
The pump does not deliver water or
has a very low flow rate or delivery
head
The motor does not reach the rated
speed
Inability to operate under load after
start-up
Presence of voltage on the motor
housing
Abnormal heating of the external
surface of the motor
Sudden loss of speed
Magnetic noise,
sudden whistle
Mechanical noise
Installation and operating instructions Wilo-SiFire FIRST
Faults, causes and remedies
CAUSE
Thermal protection triggered
Switchgear failure/incorrect connec-
tions
Change the direction of rotation
Suction depth too high. Pump cavita-
tion
Piping and suction valves of unsuitable
diameter. Pump cavitation
Air entering the suction line
Partially/totally closed shut-off valves Open the suction and discharge valves
Worn pump
Pump impeller blocked
Clogged filters
The motor does not reach the rated
speed
Voltage too low at the ends of the
motor
Uncertain contacts in the power con-
tactor or starting device failure
Phase failure
Uncertain contact in power cables
Earthing or short-circuit at winding
Insufficient sizing of the switch and
fuses of the power supply line
Insufficient voltage
Pump blocked
Exchange between line and ground
cables
Wet or aged insulation
Short-circuit between terminals and
outer housing
Overload for partially blocked pump
Ambient temperature higher than
40 °C
Voltage below/above nominal value
Lack of a phase
Unbalanced voltages on the three
phases
Instantaneous overload/foreign body
in the pump
Single-phase operation
Voltage drop
Short-circuits in the motor winding
Slip between stator and rotor
Loose bolts
Fan cover screws loosen
Swipe between fan and motor cover
Foreign bodies in the motor or pump
REMEDIES
Check the configuration of the power supply line. Check
that the pump is not blocked, check the pressure switch
calibration and the pre-charge of the autoclave tank
Check
Reverse two feeding phases
Review calculations based on NPSHr value from pump
Review calculations based on NPSHr value from pump
Check that there are no leaks in the suction line
Check and repair
Check and repair
Check and repair
See next item
Check supply voltage, connections and cable cross-sec-
tions on the supply line
Check and repair
Check line, connection and fuses
Check the tightening of the terminals
Dismantle the motor and have it repaired at the factory
Resize and replace
Check the power supply
Remove the rotating part and check
Check the electrical connections
Dry the motor or rewind it
Check the insulation between terminals and housing.
Dismantle and check
Conditioning the environment
Check the upstream power supply
Check power supply and fuses
Check the power supply
Disassemble the pump
Check power supply and fuses
Check the power supply
Have it repaired at the factory
Have it repaired at the factory
Check and tighten
Check and tighten
Ensure correct distance and reassemble
Dismantle and remove
en
79