9. TROUbLESHOOTING
Pump does not run when the motor starter is activated.
∙ Supply failure or no power supply. =
Check connections or restart the power supply.
∙ Main contacts in motor starter are not making contact or
the motor coils are defective. =
Reconnect or replace contacts or magnetic coil.
∙ Pump or auxiliary circuits protection fuses blown. =
Replace fuses.
∙ Pump or piping system may be obstructed causing a jam.=
Clean the obstruction and restart pump.
∙ Motor may have failed. = Replace the motor.
∙ Motor protector or thermal relay has tripped out. =
Reset the motor or thermal protector.
∙ Tripping of dry running protection. =
Check the water level in the tank or the water system
pressure. If everything is in order, check the protection
device and its connection cables.
Starter overload trips immediately when the power is
switched on.
∙ Overload setting is too low. =
Set the motor starter correctly.
∙ The cable connection is loose or faulty. =
Fasten or replace the cable connection.
∙ One fuse is blown. = Replace fuse and try starting again.
∙ Pump is jammed by an obstruction =
Check and clean obstruction from system.
∙ Contacts in overload are faulty. =
Replace motor starter contacts.
∙ The motor winding is defective. = Replace the motor.
∙ Low voltage (Especially at peak time). =
Check the power supply.
The pump starts but, after a short time, the thermal pro-
tector trips out or the fuses blow.
∙ The voltage is not within the motor's operating limits. =
Check the operating conditions of the pump.
∙ The control panel is situated in an excessively heated area
or is exposed to direct sunlight =
Protect the control panel from heat sources and from the
sun.
∙ A phase in the power supply is missing. =
Check the power supply.
The pump starts but, after a period of time, the thermal
protector trips.
∙ Worn motor bearings causing motor to overheat.=
Replace motor bearings.
∙ The Pump's delivery rate is higher than the specified rate
on the pump nameplate. =
∙ Partially close the on-off valve on the discharge side of the
pump until the delivery rate is within the specified limits.
∙ There are obstructions inside the pump or pumping sys-
tem. = Disassemble and clean the pump and piping.
∙ More viscous liquids may cause the pump to overload the
motor, causing the motor to overheat. =
Check the actual power requirements based on motor, the
characteristics of the liquid being pumped, replace the
motor accordingly.
Pump runs but no water is delivered
∙ Pump is not primed with liquid. =
Fill the pump with the liquid to be pumped.
∙ The pump, suction or discharge pipes are blocked by
solids in the liquid being pumped. =
Clean the pump, suction or discharge pipe.
∙ The foot or check valve is blocked or has failed. =
Replace the foot or check valve.
∙ The suction pipe leaks. =
Repair or replace the suction pipe.
∙ e. Air in the suction pipe or pump. =
Remove trapped air from system.
∙ Motor operating in wrong direction (three-phase motor). =
Change the direction of rotation of the motor by reversing
motor connections.
The pump capacity is not constant.
∙ The pump draws in air or the inlet pressure is too low. =
Improve the suction conditions.
∙ The pump or the suction side of the piping system partly
blocked by foreign bodies. =
Clean the pump or suction pipe.
The system's general protection cuts in.
∙ Short circuit. = Check electrical system.
The pump rotates in the wrong direction when switched
off.
∙ The foot or the check valve has failed. =
Check and replace check valve.
∙ Leakage in the suction pipe. =
Repair or replace the suction pipe.
The frequency of pump start-up is too high.
∙ Leakage in the foot valve, check valve or system. =
Repair or replace the components.
∙ Ruptured membrane or no air pre-charge in surge tank. =
See relevant instructions in surge tank's manual.
Vibration and noise.
∙ Cavitation = Reduce the required flow or improve the ope-
rating conditions of the pump (suction conditions, head,
flow resistance, liquid temperature, viscosity, etc.).
∙ b. Make sure that pump and motor shafts are properly
aligned. = Adjust the pump and/or motor shafts.
∙ Worn motor bearings. = Replace the bearings or the
motor.
∙ d. Operation with frequency converter. = Consult a quali-
fied engineer form the supplier of the frequency converter.
∙ Check vibration and noise damping devices =
Replace vibration & noise dampers, if worn.
ENGLISH
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