Stübbe ETLB-S series, Original Operating Manual

Page: 23 / 33

Troubleshooting
8 Troubleshooting
If faults occur which are not speci ¿ ed in the following table or
cannot be traced back to the speci ¿ ed causes, please consult
the manufacturer.
Possible faults are identi
¿ ed by a fault number in the table
below. This number identi ¿ es the respective cause and rem-
edy in the troubleshooting list.
Fault Number
Pump not pumping 1
Pumping rate insuf ¿ cient 2
Pumping rate excessive 3
Pumping pressure insuf ¿ cient 4
Pumping pressure excessive 5
Pump running roughly 6
Pump leaks 7
Excessive motor power uptake 8
Tab. 5 Fault/number assignment
Fault number
1 2 3 4 5 6 7 8
Cause Remedy
X
– – – – – – –
Pressure pipe closed by ¿ tting Open the ¿ tting.
X X
–
X
–
X
– –
Pump or suction strainer blocked or
encrusted Clean intake/suction pipe, pump or
suction strainer.
X
– – – – – – –
Transport and sealing cover still in place Remove the transport and sealing cover.
— X — X — X — — Back pressure of the system is too high,
pump selected is too small.
Consult the manufacturer.
–
X
–
X
–
X
– –
Suction head too large: NPSH
pump
is larger
than NPSH
system
Increase pump inlet pressure.
Consult the manufacturer.
X
– – – –
X
– –
Intake/suction pipe and pump not correctly
vented or not completely
¿ lled
Completely ¿ ll and vent pump and/or
pipe.
X X
–
X
–
X
– –
Air is sucked in Check the ¿ lling level of the container.
X X
–
X
–
X
– –
Proportion of gas too high: pump is
cavitating Consult the manufacturer.
–
X
–
X
–
X
– –
Temperature of À uid is too high: pump is
cavitating
Increase pump inlet pressure.
Lower temperature.
Contact the manufacturer.
–
X
–
X
– – –
X Viscosity or speci ¿ c gravity of the pumped
liquid outside the range speci ¿ ed for the
pump
Consult the manufacturer.
X X
–
X
– – – –
Geodetic differential head and/or pipe À ow
resistances too high
Remove sediments from the pump
and/or pressure pipe.
Install a larger impeller and consult the
manufacturer.
–
X
– –
X X
– –
Pressure-side ¿ tting not opened wide
enough
Open the pressure-side ¿ tting.
X X
– –
X X
– –
Pressure pipe blocked Clean the pressure pipe.
301 356 BA-2018.01.25 EN ETLB-S, ETLB-ST 23