
21
A.0500.251 – IM-TL/13.00 EN (08/2009)
2.7 Trouble shooting chart
Symptom
Causes
Actions
No flow
Irregu-
lar flow
Low
capacity
Pump
over
-
heats
Motor
over
-
heats
Exes-
sive
rotor
wear
Exes-
sive
seal
wear
Noise/,
V
ibra-
tions
Seizure
Pump
stalls on
start up
•
Incorrect direction of rotation
Reverse motor
•
Pump not primed
Expel gas from suction line/pump chamber and
prime
•
•
•
•
Insufficient NPHS available
Increase suction line dia and static suction head
Simplify suction line and reduce length
Reduce pump speed and product temperature
•
•
•
Product vapourising in suction line
•
•
•
Air entering suction line
Remake pipework joints
•
•
•
•
Gas in suction line
Expel gas from suction line/pump chamber
•
•
•
Insufficient static suction head
Raise product level to increase static suction
head
•
•
•
•
Product viscosity too high
Decrease pump speed/increase product tempe-
rature
•
Product viscosity too low
Increase pump speed/decrease product tempe-
rature
•
•
•
•
•
Product temperature too high
Cool product/pumping chamber
•
•
Product temperature too low
Heat product/pumping chamber
•
•
•
•
Unexpected solids in product
Clean the system/fit strainer on suction side of
pump
•
•
•
•
•
•
•
Discharge pressure too high
Check for blockages/simplify discharge line
•
•
•
•
•
Rotorcase strained by pipework
Check pipe alignment/support pipework
•
•
Pump speed too high
Decrease pump speed
•
Pump speed too low
Increase pump speed
•
•
•
•
•
•
Seal flush inadequate
Increase seal flush to required pressure/flow
•
•
•
•
•
•
•
Bearing/timing gear wear
Replace worn components