Wilo PNV 25-125 - 13 Annexures-2 Pre-Commissioning & Commissioning Formats

Installation and operating instructions WILO Mather and Platt – Sump Pumps 31
NOTE:
The above faults, causes and remedies are for pump only. Refer Motor / Engine manufacturers manual for the respective faults,
causes and remedies.
Causes Remedies
21
Operation at very low capacity Check the causes and refer to M&P, operate pump at rated
Duty
22
Parallel operation of pumps unsuitable for such Refer to WILO Mather and Platt with characteristics curves of pump
Operation
23
Foreign matter in impeller Open and clean
24
Misalignment Check with Dial gauge should be within limits and without
undue pipe stresses
25
Foundations not rigid Check, vibration on mount plate, check hollowness
26
Shaft bent Dismantle and check, Replace shaft
27
Rotating part rubbing on stationary part Incorrect assembly, correct the assembly
28
Bearing worn Check lubrication, shaft run out, alignment, replace if required
29
Wearing rings worn Replace
30
Impeller damaged Replace
31
Casing gasket defective, permitting internal Replace
leakage
32
Shaft or shaft sleeves worn or scored at packing Replace
33
Packing improperly installed Use correct grade and size of packing
34
Type of packing incorrect for operating Use correct grade and size of packing
condition
35
Shaft running' out of center because of worn Rectify
bearings or misalignment
36
Rotor out of balance, causing vibration Balance the rotor
37
Gland too tight, resulting in no flow of liquid to Adjust gland. Ensure sealing water flow
lubricate packing
38
Cooling liquid not being provided to water- Provide
cooled stuffing boxes
39
Excessive clearance at bottom of stuffing box Check pumps assembly
between shaft and casing, causing packing to be
forced into the pump
40
Dirt or grit in sealing, liquid leading to scoring of Provide clean liquid for flushing
shaft or shaft sleeve
41
Excessive thrust caused by mechanical failure Check pump operation and assembly
inside pump or by failure of hydraulic balancing
device, if any (in case of multistage pump etc.)
42
Excessive grease or oil in antifriction bearing Attend
housing or lack of cooling, causing excessive
bearing temperature
43
Lack of lubrication Provide proper lubrication
44
Improper installation of antifriction bearings Rectify or replace bearing
(damage, incorrect assembly of stacked bearings,
use of unmatched bearings as a pair etc.)
45
Dirt in bearings Investigate the cause and clean bearing.
46
Rusting of bearings from water in housing Arrest water ingress
47
Excessive cooling of water- cooled bearing, Reduce cooling water flow
resulting in condensation of atmospheric moisture in
bearing housing