Carrier 16DF013-050 - Manual (Page 50)

Burner Checks and Adjustments — Refer to the
burner manual for specific burner checkout and adjustment
procedure.
Service Valve Diaphragm Replacement — To re-
place valve diaphragms:
1. Break machine vacuum with nitrogen. Solution and re-
frigerant can be transferred to opposite sumps within the
machine or removed from the machine. If solution is re-
moved from the machine, store it in clean containers for
recharging.
2. Remove old valve diaphragms and replace. Torque valve
bolts to approximately 3 lb ft (0.4 kg m).
3. Test all affected connections for leakage (see Machine Leak
Test section, page 46).
4. Replace solution and refrigerant in machine (in a quan-
tity equivalent to what was removed).
5. Reevacuate machine after servicing (see Machine Evacu-
ation section, page 48).
Hermetic Pump Inspection — Figure 37 is a sec-
tional structural schematic of a typical refrigerant or solu-
tion pump used on the 16DF machine. These centrifugal pumps
are hermetic and do not require seals. The rotor assembly is
enclosed in a thin stainless steel can, and some of the pump
discharge liquid (refrigerant or solution) is circulated around
the rotor assembly for cooling the motor and for lubricating
the bearings. The following instructions are general proce-
dures for a typical pump version. Details will vary slightly
for different pump models.
Never run hermetic pump motor dry. Even momentary
operation without machine filled with liquid will dam-
age bearings and overheat the motor. Use only the cur-
rent value specified in the control circuit diagram when
setting the pump starter overloads.
DISASSEMBLY
Disconnect all primary power to the pumps; lock and
tag all disconnect switched.
1. Break vacuum with nitrogen if not already performed.
2. Remove solution and refrigerant from the machine. Store
in clean containers until recharging.
3. Open the motor wiring terminal box (Item 11) and dis-
connect the motor power leads. Mark the leads to en-
sure proper reassembly.
4. Remove nuts (Item 21) holding motor adapter flange to
pump casing (Item 23). With the larger motors which
have a hanger support, disconnect the hanger. Place match-
ing orientation marks on the two flanges.
NOTE: Use blocking to support the weight of the
motor before moving it and before removing hanger
support.
5. If pump has a circulation pipe (Item 1) connected to the
pump discharge pipe, disconnect the circulation pipe at
this time.
6. Use jackscrew to loosen motor from pump casing. Pull
motor straight back from pump casing until impeller (Item
25) has cleared the housing.
7. Remove and discard casing flange gasket (Item 22).
8. Straighten locking tabs on impeller locking washer (Item
30), and remove locking screw (Item 31). Prevent im-
peller from rotating while removing the locking screw.
9. Remove impeller with impeller/gear puller. Remove shaft
key (Item 32).
10. Remove bolts (Item 24) for motor wear ring housing (Item
33), and, using one bolt as a jack screw, carefully loosen
the wear ring housing from the motor adapter flange.
Place matching orientation marks on the two pieces. Pull
the wear ring housing straight back from the motor while
supporting the impeller shaft (Item 17), being careful to
not damage the bearings or the stator and rotor cans
(Items 14 and 15).
11. Remove the impeller end radial and thrust bearings (Items
34 and 35), and mark them for both location and direc-
tion (i.e., which end of the bearing faces the impeller
end of the motor).
12. While continuing to support the impeller shaft, pull the
rotor (Item 16) straight out of the rotor cavity, being care-
ful to not damage the bearings or the stator and rotor
cans.
13. Remove the bolts (Items 3 and 40) from the circulating
pipe connecting flange(s), if not previously done, to dis-
connect the pipe from the end of the motor.
14. Remove and discard O-rings (Items 2 and 39).
15. Remove the bolts (Item 4) on the motor end cover (Item
5) and use one as a jacking screw to loosen the end cover
from the motor end flange. Place matching orientation
marks on the two pieces. Remove the cover.
16. Remove the motor end radial and thrust bearings (Items
7 and 8), and mark them for both location and direction
(i.e., which end of the bearing faces the impeller end of
the motor).
17. NOTE: Remove and discard motor end cover gasket
(Item 6).
NOTE: Do not remove the plug (Item 18) on the top of the
motor (Item 12) except when leak testing or drying the mo-
tor windings.
INSPECTION
1. Check recirculation passages in motor and recirculating
pipe. Clean if necessary.
2. Inspect rotor and stator cans for scratches, rubbing,
or punctures. Severe damage will require motor
replacement.
3. Inspect the radial bearing cavities in the motor end cover
and wearing housing. If the internal surface is rough or
worn more than the maximum diameter in Table 17, re-
place the part.
Table 17 — Maximum Radial Bearing Cavity
Measurement
MOTOR SIZE MAX. DIAMETER (D)
kW in. mm
1.5 1.27 32.3
3.7 1.51 38.3
5.5 1.98 50.3
7.5 1.98 50.3
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