Carrier 50HQ - Manual (Page 12)

4. Disconnect compressor wiring at compressor
terminal box.
5. Using a tubing cutter, cut suction and dis­
charge lines at convenient place near com­
pressor for easy reassembly to new compressor
with copper slip couplings.
CAUTION: Excessive movement of copper
lines at compressor may cause a break
where lines connect to coil.
6. Remove compressor holddown bolts and lift
compressor out.
7. Carefully unbraze suction and discharge line
piping stubs from compressor. If oil vapor in
piping stubs ignites, use quenching cloth.
8. Braze piping stubs (removed in step 7) on new
compressor.
9. Clean system.
10. Install new compressor in unit. Braze suction
and discharge lines to compressor piping stubs
(at points where cut, step 5) using field-
supplied copper couplings. Ensure compressor
holddown bolts are in place. Connect wiring.
11. Evacuate and recharge unit.
CAUTION; Before performing recommended
maintenance, be sure main power switch to unit
is turned off.
Lubrication
COMPRESSOR contains factory oil charge. Re­
place oil when lost. See Table 6 for oil recharge. If
necessary, refer to Carrier Standard Service Tech­
niques Manual, Chapter 1, pages 1-21, for oil
recharging procedure. Use Carrier PP33-1, Texaco
Capella B or Suniso 3G oil.
FAN MOTOR BEARINGS are prelubricated for 3
years heavy-duty or 5 years normal-duty service.
Cleaning Coil and Condensate Pan — Clean
and inspect coil, condensate pan and drain before
each cooling season.
1. Remove coil section access panels and slide air
filter out of filter flanges.
2. Disconnect condensate drain line at pan drain
connection.
3. Use vacuum cleaner nozzle to clean the face of
coil.
4. Clean condensate drain trap with a bottle brush.
Clean condensate pan.
5. Hold pail under condensate pan drain connec­
tion and flush pan out with clean water. Ensure
water flows freely thru condensate drain. Do
not overflow pan.
6. Reconnect condensate drain line.
7. Install access panel and air filter.
Indoor Fan Wheel should be centered in housing.
To adjust fan, loosen setscrew holding fan to
motor shaft. Adjust fan and retighten setscrew.
50VQ INDOOR BLOWER ASSEMBLY
REMOVAL
1. Remove fan section access panel.
2. Remove power wires from Molex plug.
3. Place a spacer beneath blower housing for
support.
4. Remove blower assembly mounting bracket.
(Rear flange on top of blower housing and
screws now hold blower assembly in place.)
5. Support blower housing at bottom and remove
spacer. Tilt blower assembly downward and lift
out of unit.
50HQ INDOOR BLOWER ASSEMBLY
REMOVAL
1. Remove top cover (Fig. 2).
2. Remove power wires from Molex connector
(Fig. 7).
3. Remove blower assembly mounting screws from
base unit (Fig. 2).
4. Lift blower assembly out of unit.
Indoor Fan and Motor Removal
1. Remove blower assembly from unit.
2. Remove Molex plug from bracket on fan
housing.
3. Loosen setscrew holding fan to motor shaft.
4. Loosen motor mounting band and remove
motor.
5. Remove fan cutoff plate from blower housing
outlet.
6. Remove fan wheel from blower housing outlet.
Clean Indoor Fan Wheel — When coil is cleaned,
remove caked-on dirt from fan wheel and housing
with brush; remove grease with mild solvent. When
replacing blower assembly, make sure fan wheel is
centered in housing.
Return Air Filter — Replace filter media 4 times a
year. For other types of filters, refer to filter manu­
facturer’s instructions as required.
CAUTION; Nev«r operate unit W3tltcwi.t a filter
as coil wilt plug and damage to fan motor may
result.
Heat Exchanger — If excessive discharge pressure
is experienced with normal water flow, the heat
exchanger tubes may be fouled and require cleaning.
Contact a local water treatment firm for details on
chemical cleaning.
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