6
Problem How to check Remedy
1 Motor does
not start.
No noises
or vibrations
occur
2 Motor does
not start,
but generates
noises and
vibrations
A - Make sure that motor is wired up as
directed in the diagram inside the terminal
box cover.
B - The shaft is bound. Find out if due to loose
fan or mechanical obstructions on the
motor or the pump.
C - The sliding surface of mechanical seal is
stuck due to prolonged stoppage.
A - Correct any wrong
connections.
B - Remove cause of obstruction.
C - Correct seal by turning the
shaft - 1/4 turn with a pipe
wrench.
3 Pump
does not
provide
delivery
A - Pump has not been filled.
B - Pump has unprimed due to leaks in the
suction line.
C - With 3phase motors check for correct
direction of rotation.
D - The head required by the plant is higher
than that generated by the pump.
E - Foot valve clogged.
F - Suction lift too high.
G - Suction pipe too narrow.
A - Fill the pump. Prime it again.
B - Repair leaks. Fill and prime
again.
C - Interchange two supply leads.
D - Replace the pump with a
suitable one.
E - Clean foot valve.
F - See section “installation”.
G - Replace suction pipe with one
having diameter larger by 1/4”
or 1/2”.
A - Make sure that power supply
is connected.
B - Check for any blown fuses.
C - Check for open or dirty contacts in the
protection devices.
B - Replace fuse with new one.
Note: if the new fuse blows immediately
after, the motor or the cable are shorted,
either directly or the earth (faulty insulation).
C - Clean the part involved or
replace it with a new one.
4 Protection
trips
as machine
starts
A - One phase is missing.
B - As in 1B.
C - As in 1C.
D - Motor with faulty insulation; check phase
resistance and insulation to ground.
A - Reset the phase
B - As in 1B.
C - As in 1C.
D - Replace stator or the internal
earth cable.
8. Fault finding chart: problems, possible causes and remedies
INSTRUCTIONS FOR THE INSTALLATION AND USE OF ELECTROPUMPS
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