Carrier 50ET - Manual (Page 10)

HEATING A COOLING
50ET,QT
Single-Package Units
5. Disconnect compressor wiring at compressor
terminal box.
6. Using a tubing cutter, cut suction and discharge lines
at convenient place near compressor for easy re­
assembly to new compressor with copper slip
couplings.
A CAUTION
Excessive movement of copper lines at com­
pressor may cause a break where lines connect
to other .system components.
7. Remove crankcase heater from compressor base.
8. Remove clamp holding accumulator to shell.
9. Remove compressor holddown bolts and lift com­
pressor out, sliding and tipping it towards the
outside,
10. Carefully unbraze suction and discharge line piping
stubs from compressor. If oil vapor in piping stubs
ignites, use quenching cloth.
11. Braze piping stubs (removed in step 10) on new
compressor, in same position as before.
12. Install new compre.ssor in unit. Braze suction and
discharge lines to compressor piping using field-
supplied copper couplings. Ensure compressor hold­
down bolts are in place. Reinstall crankcase heater.
Connect wiring.
13. Triple-evacuate to 5000 microns and recharge unit.
See Refrigerant Charging section.
14. Refer to NOTE at the end of this section for
important information.
Compressor Removal — 50ET.QT218,
224,230
1. Shut off power to unit. Remove chassis indoor cover.
Fig, 1.
2. Remove chassis to truck or shop.
3. Remove refrigerant from unit using refrigerant re­
moval methods described in Carrier Standard Serv­
ice Techniques Manual, Chapter 1, Refrigerants.
4. Remove core from suction and discharge line
Schrader valves.
5. Remove outdoor fan guard.
6. Remove outdoor compressor guard.
7. Remove outdoor propeller fan.
8. Remove outdoor fan orifice ring by removing 4
screws attaching it to outdoor fan motor bracket.
9. Remove 3 of 4 outdoor fan motor bolts, leaving
bolt at upper right of fan motor in place. Rotate
motor up and out of the way by hinging it on remain­
ing bolt. Use wire or solder to tie outdoor fan
motor to
outdoor coil support on top side of coil.
10. Using a miniature tubing cutter, cut compressor
suction tube on short vertical run as tube enters
compressor.
11. Cut compressor discharge tube on horizontal tubing
run approximately 6 to 12 in. from where it leaves the
compressor. Keep crankcase heater thermostat on
right side of cut so it stays in place when compressor
is removed.
12. Disconnect compressor wiring at compressor ter-
minal box. Remove compre.ssor wires and crankca.se
heater splice from box.
13. Using an 18-in. long extension on ratchet wrench,
remove 4 compressor holddown bolts.
14. Slide compressor out to edge of pan. Remove crank­
case heater by loosening worm drive clamp and
sliding over top of compressor.
15. Remove compressor from pan.
16. Carefully unbraze suction and discharge line piping
stubs from compressor. If oil vapor in piping stubs
ignites, use quenching cloth.
17. Braze piping stubs (removed in step 16) on new com­
pressor, in same direction as before.
18. Using field-supplied copper couplings, install new
compressor in unit.
19. Reassembly is reverse of above procedure.
20. Triple-evacuate to 5000 microns and recharge unit.
See Refrigerant Charging section.
NOTE. If a compressor failure was caused by motor
winding burnout, the by-products of the burnout
must be separated from the circulating refrigerant.
This must be done before the by-products enter the
reversing valve or accumulator and render parts
inoperative. Burnout by-products can cause future
system operating problems if left in the system.
Clean the .system by installing a suction line drier in
the refrigerant line where the suction gas enters the
reversing valve. During the cooling cycle, this is the
line from the indoor coil running to the compressor
compartment; during heating cyele, install drier in Br
line between outdoor coil and reversing valve. If
possible, run unit in cooling mode when cleaning
.system as no defrosting occurs.
To provide protection for the reversing valve, do not
place filter d rier between reversing valve and accumu­
lator. Since the suction drier works on one mode
only, temporarily wire the unit in the selected mode
(heating or cooling, based on suction drier location),
ifo insure cooling operation only, install a jumper
between terminals no. 1 and no. 4 on receptacle no. 3.
For heating operation only, remove and insulate
one of the reversing valve solenoid leads. Run unit for
2 hours and check oil for acidity. If satisfactory,
remove suction line drier. Refer to and follow pro­
cedure under AccuRater^“ Servicing for cleaning of
AccuRater. Rewire unit to normal condition.
Lubrication — Compressor contains factory oil
charge. Replace oil when lost. See Table 4 for oil re­
charge. If necessary, refer to Carrier Standard Service
Techniques Manual, Chapter 1, Refrigerants, page 1-21,
for oil recharging procedure. Use Carrier PP33-1,
Texaco WF-32 or Suniso 3GS oil.
FAN MOTOR BEARINGS — Oiling holes are provided
at each end of outdoor fan motor. Remove fan motor and
lubricate motor with 32 drops (16 drops per hole) of
SAE 10 nondetergent oil at intervals described below:
a.
Annually when environment is very dirty, ambient
temperature is higher than 105 F and average unit
operating time exceeds 15 hours a day.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obiigations.
Bookll 11 |4 |4 PC131 CataloaNo 535-078 PrintedinUSA Form50ET.QT-3SI PglO 5-85 Replaces: S0QT-10SI
Tab Ilbl5allal5a
Catalog No 535-078 Printed in U S A Form 50ET.QT-3SI
For replacement items use Carrier Specified Parts