Carrier WeatherMaster 50HCQA04, Service And Maintenance Instructions, Page: 19 / 98

19
Replacing Compressor
!
WARNING
FIRE, EXPLOSION HAZARD
Failure to follow this
warning could result in
death, serious personal
injury and/or property
damage.
Never use air or gases containing oxygen for leak testing
or for operating refrigerant compressors. Pressurized
mixtures of air or gases containing oxygen can lead to an
explosion.
INSTALLATION SITE DAMAGE
Failure to follow this caution can result in damage to
equipment location site.
S
Puron (R--410A) refrigerant contains polyolester
(POE) oil that can damage the roof membrane.
Caution should be taken to prevent POE oil from
spilling onto the roof surface.
S
The factory also recommends that the suction and
discharge lines be cut with a tubing cutter instead of
using a torch to remove brazed fittings.
CAUTION
NOTE
: Only factory--trained service technicians should
remove and replace compressor units.
Compressors using Puron refrigerant contain a polyolester
(POE) oil. This oil has a high affinity for moisture. Do not
remove the compressor’s tube plugs until ready to insert
the unit suction and discharge tube ends.
Compressor Rotation:
EQUIPMENT DAMAGE
Failure to follow this caution can result in equipment
damage.
Scroll compressors can only compress refrigerant if
rotating in the right direction. Reverse rotation for
extended times can result in internal damage to the
compressor. Scroll compressors are sealed units and
cannot be repaired on site location.
CAUTION
NOTE : When the compressor is rotating in the wrong
direction, the unit makes an elevated level of noise and
does not provide cooling.
On 3--phase units with scroll compressors, it is important
to be certain compressor is rotating in the proper
direction. To determine whether or not compressor is
rotating in the proper direction:
1. Connect service gauges to suction and discharge pres-
sure 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:
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 three unit power leads.
7. Reapply electrical power to the compressor.
8. The suction pressure should drop and the discharge
pressure should rise which is normal for scroll com-
pressors on start--up.
9. Replace compressor if suction/discharge pressures are
not within specifications for the specific compressor.
Filter Drier
Replace the Filter Drier whenever refrigerant system is
exposed to atmosphere. Only use factory specified
liquid--line filter driers with working pressures no less
than 650 psig (4482 kPa).
EQUIPMENT DAMAGE
Failure to follow this caution can result in equipment
damage.
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.
CAUTION
Outdoor Fan Location
See Fig. 27.
1. Shut off unit power supply. Apply lockout/tagout pro-
cedures.
2. Remove condenser--fan assembly (grille, motor, and
fan).
3. Loosen fan hub setscrews.
4. Adjust fan height as shown in Fig. 27.
5. Tighten setscrews to 84 in--lbs (9.5 Nm).
6. Replace condenser--fan assembly.
CONDUIT
0.14 in +0.0/-0.03
C08448
Fig. 27 -- Outdoor Fan Adjustment
Troubleshooting Cooling System
Refer to Table 6, on the following page, for additional
troubleshooting topics.