SPERONI CS Serie Instrucciones De Uso página 15

8. Fault finding chart: problems, possible causes and remedies
Problem
5 Protection
trips
too often
6 Shaft
spins
with difficulty
7 Pump
vibrates, runs
noisily;
flow rate
is uneven
8
When stopped,
the pump runs
slightly in reverse
direction
9
In pressure
boosting
applications the
pump starts and
stops too often
10
In pressure
boosting
applications, the
pump does not stop
How to check
A - Ascertain whether the protection device is
set to a value lower than the motor full load
requirements.
B - One phase is missing due to faults in
contacts or supply cable.
C - Liquid is viscous or its specific weight is
much higher than that of water.
D - Harsh rubbing occurs between sliding and
stationary parts.
A - Check for obstructions in the motor or the
pump.
B - As in 5D.
C - Check bearings for proper conditions.
A - Pump runs beyond rated capacity.
B - Pump or pipework not properly secured.
C - As in 3F.
D - As in 3G.
A - Leaks or air locks in suction pipe.
A - Pressure-switch setting is too limited.
B - Leaks in system.
A - Max.-pressure setting in pressure switch
is too high.
B - As in 9B
A - Correct setting.
B - Clean and reset contact or
C - Reduce flow rate slightly by
D - Remove cause of harsh
A - As in 2B.
B - As in 5D.
C - Replace any faulty bearing.
A - Reduce flow rate.
B - Secure any loose or improperly
C - As in 3F.
D - As in 3G.
A - Correct leaks and read section
A - Set pressure switch to wider
B - Eliminate leaks.
A - Reduce max-pressure setting
B - As in 9B.
7
13
Remedy
replace supply cable with new
one.
adjusting the delivery sluice
valve accordingly. If this is not
acceptable, instal a more
powerful motor.
rubbing.
secured part.
"installation".
limits.
to lower value.