Faults, Causes And Remedies - Wilo Drain SP Série Notice De Montage Et De Mise En Service

10 FAULTS, CAUSES AND REMEDIES

Fault Cause
- Pump had to be stopped before it was primed
- No liquid in priming chamber or liquid level is too
low
- Air intake in suction line
- Impeller or casing wear plate is worn
Pump does not
- Liquid temperature in pump is to high
prime
- Pressurized discharge pipe
- Motor speed is too low
- Air intake through the shaft sealing. Leaking
mechanical seal.
- Wrong motor direction of rotation
- Discharge pressure is too high
- Pump or piping is not completely vented
- Suction lift is too high / NPSH available is too low
The pump is not
producing the rated
- Clearance between the impeller and the wear
flow or head
plate(s) is excessive
- Wrong direction of rotation
- Leakage on pump casing gaskets, on shaft sealing
or on suction piping
- Air leaks into pump through mechanical seal,
sleeve, clogged strainer or leakage in suction line
Pump is not lifting - Suction lift is too high or head losses in suction line
liquid are excessive
- Too much foreign matter in pump casing or part
blocked inside the impeller
- Casing seal(s) leaking
The pump leaks
- Mechanical seal is leaking
- Ball bearing in bearing bracket or in motor is worn
or destroyed
- Incorrect inflow of circulation liquid
- Suction head is too high or discharge head to low
The pump runs
noisily
- Wrong assembly of the base plate on its
foundations or unauthorized forces applied to
pump flanges
- Foreign matter remains inside the pump casing
- Current leakage
- Protection fuses not calibrated properly
Motor protection
switches off
- Liquid density higher than expected
- Pump runs right of curve or out of application
limits
- Foreign matter remains inside the pump casing
Remedy
Check theoretical priming time
Check that grease cartridge was activated
Check that temperature sensor trip is set properly (ATEX versions)
Fill pump casing with fluid
Check level switches position
Check shape of connections and threads
Check tightening of hoses fastening collars
Proceed with replacement of damaged hoses
Do sealing operations again if necessary
Replace wear plate or impeller
Check pump working conditions
Fill the pump with cold liquid
Add a vent valve between the check valve and the discharge flange or add a
dedicated discharge pipe back to the pit
Check tightening of power supply cable connections
Check motor current consumption
Increase frequency up to 50Hz (if a frequency inverter has been supplied)
Replace grease cartridge
Replace mechanical seal
In case of emergency : grease copiously mechanical seal faces and back of the
stationary seat with high viscosity grease
Change two phases in motor junction box
Open and clean discharge pipe
Check pump duty point
Vent pump casing and suction line
Check fluid level in the tank and check max flow according to pump curve
Check isolating valve is opened on the pump suction side
Clean the strainer if any
Check wear plate(s) thickness
Replace worn wear plate(s) by new one(s)
Change two phases in motor junction box
Replace casing seal(s)
Check shaft sealing
Check the state of the flanges seals
Replace casing seal(s)
Check shaft sealing
Check the state of the flanges seals
Check fluid level
Check that the available NPSH of the process is higher than the required NPSH
of the pump
Open visit port and clean the inside of the pump
Tighten bolts and screws according the provided tightening torque values
Check the state of the gaskets
Check the state of the mechanical seal faces and O'Ring
Proceed with replacement of the mechanical seal
Replace grease cartridge by a new one
Replace ball bearings
Cavitations : check pump duty point
Check fluid level in the tank and open all valves set on suction pipe
Check pump discharge pressure
Clean the strainer
Check pump installation
Check lining of coupling
Open visit port and clean the pump
Check earthing of the motor
Check for current leakage : damaged cables, fluid leakage on electrical
components ...
Check motor absorbed power and select motor protections accordingly.
Calculate absorbed power and replace motor accordingly
Measure pump duty point and check pump runs in authorized application
limits. If necessary add a regulating valve or a calibrated orifice on pump
discharge line
Open visit port and clean the pump
ENGLISH
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