Causes And Possible Solutions - Johnson Pump SPX Flow CombiLine Series Instruction Manual

6.2

Causes and possible solutions

A Electrical connection is faulty:
• Consult your electrician
B Wrong sense of rotation:
• Consult your electrician
C Pump not filled with liquid:
• Open valves
• Fill pump with fluid
• De-aerate the system
D NPSH available too low:
• Increase the pre-pressure
• Mount the pump as low as possible in the piping
E Pump does not run at the required speed:
• Consult your electrician
F Foreign particles inside the pump:
• Dismantle and clean the pump
• If necessary mount a filter
G Air in the pipes:
• De-aerate the system
• Increase the immersion depth of the suction pipe
• Increase the liquid level at the suction side
H Required head higher than calculated:
• Change the speed
• Select another pump
I Suction pipe or possibly mounted filter blocked:
• Clean filter and suction pipe
J Damaged bearings:
• Replace bearings
• Inspect the shaft
• Check whether the impeller is not damaged
K Impeller stuck:
• Try to rotate the shaft at the rear by means of a screw driver through the hole in the fan
protecting cover
• Dismantle and clear the pump, check the shaft on straightness
30 Faults
CL-CBH/EN (1901) 7.6