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10. Fault finding the product
Before attempting to diagnose any fault, read and
observe the safety instructions in section
.
DANGER
Electric shock
Death or serious personal injury
- Before starting any work on the product,
make sure that the power supply has
been switched off and that it cannot be
accidentally switched on.
Fault
Cause
Remedy
1.
The pump does
not start.
a)
A fault signal is indicated.
• If the bearing temperature is high, take the pump
to the workshop for repair.
• If the stator temperature is high, make sure that
the water can move around the stator housing
without any obstacles, and that the propeller or
impeller rotates easily.
• If there is a fault in the thermal protectors, contact
an authorised electrician. Check that the overload
protection is reset.
b)
The pump cannot be
started manually.
Check the following and, if necessary, take corrective
action:
• Are the control voltage and control fuse OK?
• Are all connections securely tightened?
• Are the relay and contactor coils functioning
correctly?
c)
A fault signal is indicated
on the control panel.
Check the following and, if necessary, take corrective
action:
• Is the supply voltage correct on all phases?
• Is the main power switch on and are the fuses
intact?
• Has the overload protection been reset?
• Is the power cable damaged?
2.
The pump
starts, but the
motor protection
stops it after a
few seconds.
a)
The motor protection is
set too low.
• Check the motor data in the nameplate.
• Adjust the settings of the motor protection.
b)
It is difficult to rotate the
propeller or impeller by
hand.
• Clean the propeller or impeller of fibres and rags.
• Clean out the pit.
c)
The voltage is not the
same on all three phases.
Contact an authorised electrician.
d)
The phase currents are
unbalanced or too high.
Contact an authorised electrician.
e)
The insulation between
the phases and between
phases and earth in the
stator is defective.
Use an insulation resistance tester set to 1000 VDC
and check that the insulation between phases and
between phases and earth (ground) complies with
the correct levels for the type of motor.
If necessary, contact an authorised electrician.
f)
The density of the
pumped liquid is too high.
Maximum density is 1000
kg/m
3
.
Dilute the liquid.
g)
The motor protection
devices are defective.
Replace the defective motor protection devices.
