Compressor; Filter Drier; Condenser-Fan Adjustment; Troubleshooting Cooling System - Carrier WeatherExpert 48LC Series Service And Maintenance Instructions

5/8" HEX

Compressor

LUBRICATION
The compressor is charged with the correct amount of oil at the
factory.
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in damage to compo-
nents.
The compressor is in a R-410A refrigerant system and uses a
polyolester (POE) oil. This oil is extremely hygroscopic,
meaning it absorbs water readily. POE oils can absorb
15 times as much water as other oils designed for HCFC and
CFC refrigerants. Avoid exposure of the oil to the atmosphere.
REPLACING COMPRESSOR
The compressor used with Puron refrigerant contains a POE oil.
This oil has a high affinity for moisture. Do not remove the com-
pressor's tube plugs until ready to insert the unit suction and dis-
charge tube ends.
Compressor mounting bolt torque is 65 to 75 ft-lb.
COMPRESSOR ROTATION
On 3-phase units with scroll compressors, it is important to be cer-
tain compressor is rotating in the proper direction.
To determine whether or not compressor is rotating in the proper
direction:
1. Connect service gages to suction and discharge pressure
fittings.
2. Energize the compressor.
3. The suction pressure should drop and the discharge pressure
should rise, as is normal on any start-up.
NOTE: If the suction pressure does not drop and the discharge
pressure does not rise to normal levels:
1. CoreMax is a registered trademark of Fastest, Inc.
SEAT
1/2-20 UNF RH
0.596
30°
0.47
This surface provides a metal to metal seal when
torqued into the seat. Appropriate handling is
required to not scratch or dent the surface.
Fig. 11 — CoreMax
CORE
(Part No. EC39EZ067)
WASHER
O-RING
1/2" HEX
Access Port Assembly
1
4. Note that the evaporator fan is probably also rotating in the
wrong direction.
5. Turn off power to the unit.
6. Reverse any two of the unit power leads.
7. Reapply power to the compressor.
The suction and discharge pressure levels should now move to
their normal start-up levels.
NOTE: When the compressor is rotating in the wrong direction,
the unit makes an elevated level of noise and does not provide
cooling.

Filter Drier

Replace whenever refrigerant system is exposed to atmosphere.
Only use factory specified liquid-line filter driers with working
pressures no less than 650 psig. Do not install a suction-line filter
drier in liquid line. A liquid-line filter drier designed for use with
Puron refrigerant is required on every unit.

Condenser-Fan Adjustment

1. Shut off unit power supply. Install lockout tag.
2. Remove condenser-fan assembly (grille, motor, and fan).
3. Loosen fan hub setscrews.
4. Adjust fan height as shown in Fig. 12.
5. Tighten setscrews.
6. Replace condenser-fan assembly.
Fig. 12 — Condenser Fan Adjustment

Troubleshooting Cooling System

Refer to Table 1 for additional troubleshooting topics.
8
45°
DEPRESSOR PER AHRI 720
+.01/-.035
FROM FACE OF BODY
7/16-20 UNF RH
CONDUIT
0.14 in. + 0.0 / -0.03