Reassembly; Troubleshooting Chart - Xylem NPE Instruction Manual

9.4.4. Remove impeller (101) by turning counter-
clockwise when looking at the front of the
pump. Protect hand with rag or glove.
Failure to remove the impeller in
CAUTION
a counter-clockwise direction may
damage threading on the impeller,
shaft or both.
9.4.5. With two pry bars 180 degrees apart and
inserted between the seal housing (184) and
the motor adapter (108), carefully separate
the two parts. The mechanical seal rotary unit
(383) should come off the shaft with the seal
housing.
9.4.6. Push out the mechanical seal stationary seat
from the motor side of the seal housing.
9.5. Disassembly of Bearing Frame
9.5.1. Remove bearing cover (109).
9.5.2. Remove shaft assembly from frame (228).
9.5.3. Remove lip seals (138 and 139) from bear-
ing frame and bearing cover if worn and are
being replaced.
9.5.5. Use bearing puller or arbor press to remove
ball bearings (112 and 168).

10. REASSEMBLY:

10.1. All parts should be cleaned before assembly.
10.2. Refer to parts list to identify required replace-
ment items. Specify pump index or catalog num-
ber when ordering parts.
10.3. Reassembly is the reverse of disassembly.
10.3.1. Impeller and impeller locknut assembled
onto motor shaft with 10 ft-lbs (13.6 N
of torque.
10.4. Observe the following when reassembling the -
bearing frame.
10.4.1. Replace lip seals if worn or damaged.
10.4.2. Replace ball bearings if loose, rough or
noisy when rotated.
10.4.3. Check shaft for runout. Maximum
permissible is .002" (.05 mm) T.I.R.
10.5. Observe the following when reassembling the
liquid-end.
10.5.1. All mechanical seal components must be
in good condition or leakage may result.
Replacement of complete seal assembly,
whenever seal has been removed, is good
standard practice.
It is permissible to use a light lubricant,
such as glycerin, to facilitate assembly. Do
not contaminate the mechanical seal faces
with lubricant.
10.5.2. Inspect casing O-ring (513) and replace
if damaged. This O-ring may be lubricated
with petroleum jelly to ease assembly.
10.5.3. Inspect guidevane O-ring (349) and
replace if worn.
Do not lubricate guidevane O-ring
CAUTION
(349). Insure it is not pinched by the
impeller on reassembly.
6
10.6. Check reassembled unit for binding. Correct as
required.
10.7. Tighten casing bolts in a star pattern to prevent
O-ring binding.
11. TROUBLE SHOOTING CHART:
MOTOR NOT RUNNING:
(See causes 1 thru 6)
LITTLE OR NO LIQUID DELIVERED:
(See causes 7 thru 17)
POWER CONSUMPTION TOO HIGH:
(See causes 4, 17, 18, 19, 22)
EXCESSIVE NOISE AND VIBRATION:
(See causes 4, 6, 9, 13, 15, 16, 18, 20, 21, 22)
PROBABLE CAUSE:
1. Tripped thermal protector
2. Open circuit breaker
3. Blown fuse
4. Rotating parts binding
5. Motor wired improperly
6. Defective motor
7. Not primed
8. Discharge plugged or valve closed
9. Incorrect rotation
10. Foot valve too small, suction not submerged,
inlet screen plugged
11. Low voltage
12. Phase loss (3-phase only)
m)
•
13. Air or gasses in liquid
14. System head too high
15. NPSHA too low:
Suction lift too high or suction losses excessive.
Check with vacuum gauge.
16. Impeller worn or plugged
17. Incorrect impeller diameter
18. Head too low causing excessive flow rate
19. Viscosity or specific gravity too high
20. Worn bearings
21. Pump or piping loose
22. Pump and motor misaligned
12. DISPOSAL:
12.1. Observe local regulations and codes for
disposal.
13. NOISE EMISSION:
13.1. Typical sound pressure level, Lpa for close
coupled pump at BEP < 70 dB.