Carrier 73Y - Manual (Page 2)

1
Compressor Replacement — Stand dear of com­
pressor terminals when working on compressors. With sys­
tem under pressure, terminals may blow. Observe the same
.safety procedures for rotary compressors as for reciprocat­
ing compressors.
When changing compressors:
1. Follow all safety codes. Reminder, use protective
goggles, work gloves, and water-soaked quenching
cloth
2. Shut off all electrical power to unit by removing power
cord from outlet, then disconnect all wiring from the
compressor.
3. Apply field-supplied tap-a-lines to the true (closest to
compressor) suction and discharge connections of the
compressor.
Recover the refrigerant charge from the unit. After re­
covering, cut the discharge and suction line process tubes
below the tube crimps. If you choose a good tubing
location for cutting the refrigerant lines initially, the
location is easily accessible when making the final joints.
You can braze the oil piping stub into the new com­
pressor fittings more easily before the compressor is
put back into the unit.
A CAUTION
Oil vapor in piping stubs can ignite from torch flame
and cause serious injury. Exercise extreme care when
brazing, and keep brazing cloth and fire extin­
guisher handy for emergency use.
4.
5. Connect a nitrogen supply to the unit at one of the tap-
a-line connectors (5 psig maximum flow), leaving the
other connector open to the atmosphere. Braze angle
valves with stubs to each process tube.
6. Remove compressor from unit. Refer to Compressor
Removal, page 11.
7. Remove tap-a-llnes from suction and discharge lines
Carefully braze the holes closed from where the tap-a-
lines were removed.
8. Clean system: add or replace liquid line filter drier.
For proper cleaning and flushing, use the Carrier
Totalclaim® reclaim system or a comparable refrig­
erant recycling system.
9. Install new compressor and braze into place with field-
supplied copper slip couplings.
10. Connect wiring: replace wire terminals if necessary.
11. Proceed with evacuation and charging. Pinch off lines
where angle valves were added. Cut off angle valves
above pinch-off, and braze tubes.
12. Start up unit.
SAFETY REMINDERS
1. Carry a fire extinguisher in your truck. Keep it within
reach when using a torch. Check fire extinguisher peri­
odically to be sure it is fully loaded and functional.
2. Know how to handle oxyacetylene equipment safely. Lock
the equipment in an upright position in the truck and at
the job site.
3. Use dry nitrogen or carbon dioxide to pressurize the sys­
tem for leak checking. Always use a good regulator. Be
careful not to exceed 150 psig test pressure in the her­
metic compressor.
4. Wear safety goggles and gloves when recovering refrig­
erant from a system,
5. Attend shop safety meetings.
PREVENTIVE MAINTENANCE
General
CLEANING — Clean cooling coil and condenser coil. Hold
flashlight behind coil to see If all spaces are clear. Use a
hooked wire to remove dirt. Dust accumulation obstructs or
reduces airflow and results in loss of capacity. Coils may
be vacuumed when dry. Outdoors, unit can be brushed with
a stiff brush and fins blown out with compressed air.
Thoroughly clean basepan, motors, fan wheels, other com­
ponents, and all drain passages. Vacuum insulation. Clean
all Inside painted surfaces with mild detergent to remove
grease.
Clean cabinet and grille. Mild detergents reduce electro­
static charges on plastic sections of the grille and are good
cleaners. Do not use carbon tetrachloride, solvents, or waxes
containing solvents to clean plastic sections.
PAINTING — Paint any parts that show evidence of rust
with a good rust-resistant paint.
WIRING — Check all wiring for deterioration and all elec­
trical contacts for tightness and lack of corrosion.
MOUNTING — Make sure unit is secure in window, and
level from left to right and from front to rear according to
installation instructions provided.
Check fans to ensure they are correctly positioned, cen­
tered in orifice, and tight on shaft.
LEAKS — Check any connections that show evidence of
oil or leaks. When unit is properly installed, centered, and
leveled (see Owners’ Guide), check gaskets and wing pan­
els for possible air leakage.
CONTROLS — Check unit to ensure all controls are func­
tioning correctly and unit operation is normal.
Vibrations can cause unwanted noise. Check to be sure
no piping is vibrating against any side of unit.
System Cleaning/Flushing — For proper cleaning
and flushing, use the Carrier Totalclaim reclaim system, or
a comparable refrigerant recycling system.
SP