Watson-Marlow EC 25 - Manual (Page 14)

Revision 4.4 / November 2010
14
19 Troubleshooting
Error Cause Remedy
Direction of rotation not correct Check direction of rotation
No wetting liquid in the pump Fill pump with liquid
Screw fastening not tight Check screw fastening
Suction pipe too long Adapt suction pipe
Pipe cross-section too narrow Adapt suction pipe
Seals leaking Check all seals for damage
Wear in the pump Change wearing parts
Pump does not draw in
Motor speed not correct Measure, regulate speed
Direction of rotation not correct Check direction of rotation
Suction pipe is leaking Check pipe system
Motor speed not correct Check speed based on output
diagrams
Wearing parts worn Replace wearing parts
Pump does not deliver
Inserted closed gate valve Check pipe system
Noises come from the drive / pump Consult
Watson-Marlow MasoSine
Suction pipe too small (cavitation) Shorten suction pipe or increase
diameter, reduce speed
Knocking noises from the pump head Scrapergate wear
Noises from bearing housing
Fill oil, change tapered roller
bearings
Pump is noisy
Coupling not aligned Align coupling with hairline
Seal system leaking Change Mechanical or Lip seal
system
O-ring seal leaking Replace O-ring
Pump leaking at leakage
hole
Pump is noisy
Lip seals on the bearing block
leaking, oil escapes Dismantle bearing block,
replace radial shaft sealing rings
Pump leaking at the front
housing O-rings in the Liner not or wrongly
installed Install housing O-ring correctly or
replace
Foreign body in the pump Remove foreign body, examine
pump for damage
Power supply interrupted Check electrical installations
(fuses, drive)
Pump has blocked
Defect on the drive (Separate the coupling and turn
the pump by hand)
Strong wear after short
operating time Solids in the pumped material
Pumped material is abrasive Frequent change of the wearing
parts, change material pairing
Choose larger pump,
reduce speed
Rotor not tightened correctly on
installation Tighten closing nut firmly on block Rotor has wear on one
side
Adjusting dimensions changed after
working on the bearing housing Check and correct the adjusting
dimensions
(see page 12)
Pump not clean after CIP
cleaning Cleaning regulation not complied with Choke on the pressure side
Check differential pressure 3-4 bar
Rotor not correctly tightened Tighten closing nut firmly on block Rotor has seized on
stator
Temperature too high
(thermal expansion) Choose Liner with larger
tolerances