Masdaf HEXA 1, Operating Manual, Page: 9 / 16

9. POSSIBLE FAILURES, CAUSES, SOLUTIONS
Possible failures and solution strategies are listed in the table below. Please apply to the Customers’ Service Department
of our company when a generic solution is not found to your problem.
While the failures are repaired the pump must always be dry and un-pressurized.
Table 1:
Possible Failures, Causes, Solutions
HEXA Series
9
POSSIBLE FAILURE CAUSES SOLUTIONS REMARKS
Motor does not run when started.
a) Power supply failure.
b) Fuses are blown.
c) Motor is overloaded.
d) Main contacts of starter are not connected
well or the coil is defective.
e) Control circuit is defective.
f) Motor is defective.
a) Check power supply.
b) Replace fuses.
c) Check system.
d) Replace motor starter.
e) Check control circuit.
f) Repair.
Overload device of motor starter
trips out immediately when power
supply is switched on.
a) Fuses are blown.
b) Contacts of overload device are faulty.
c) Cable connection is loose or faulty.
d) Motor winding is defective.
e) Pump mechanically blocked. a) Replace fuses.
b) Check motor starter.
c) Check cables and power supply.
d) Replace motor.
e) Check and repair pump.
In the case of d) and
e), users shall not
disassemble the
pump by themselves.
Overload device trips out
occasionally.
a) The setting of overload is too low.
b) Periodic power supply faults.
c) Low voltage at peak times. a) Reset overload setting.
b) Check power supply.
c) Add regulator.
Motor starter has not tripped out
but the pump does not run.
a) Contacts of starter are not contacted well
or the coil is faulty.
b) Control circuit are defective
a) Change motor starter.
b) Check control circuit.
Pumped water does not flow
constantly.
a) Suction pipe is too small.
b) There is not sufficient water in pump water
inlet.
c) Liquid level is low.
d) Pump inlet pressure is too low compared
with water temperature, pipeline loss and
flow.
e) Suction pipe is blocked by impurities.
a) Enlarge inlet pipeline.
b) Improve system and increase
coming water.
c) Try to lift liquid level.
d) Improve system and try to
increase the inlet pressure.
e) Check and clear impurities.
Pump runs but gives no water.
a) Suction pipe is blocked by impurities.
b) Foot valve or check valve is closed.
c) Leakage in suction pipe.
d) There is air in suction pipe or pump.
a) Check and clean suction pipe.
b) Check and repair foot valve or
check valve.
c) Check and repair suction pipe.
d) Refill liquid, release air.
Pump runs backwards when
switched off.
a) Leakage in suction pipe.
b) Foot valve or check valve is defective.
c) Foot valve is blocked in opened or partly
opened position.
d) There is air in suction pipe.
a) Check suction pipe.
b) Check and repair foot valve or
check valve.
c) Check and repair foot valve.
d) Check and repair suction pipe and
release air.
Abnormal vibration or noise from
pump.
a) Leakage in suction pipe.
b) Suction pipe is too small or suction pipe is
partly blocked by impurities.
c) There is air in suction pipe or pump.
d) The comparison of the delivery head of
device with delivery head of pump is very
low.
e) Pump mechanically blocked.
a) Check and repair suction pipe.
b) Enlarge or check situation pipe.
c) Refill liquid to the pump and vent
air.
d) Improve system or choose
another pump model.
e) Check and repair pump.
In the case of e),
users shall not
disassemble the
pump by themselves.