Compressor Rotation; Filter Drier; Outdoor Fan Location; Troubleshooting Cooling System - Carrier WeatherMaster 50HCQ04-12 Service And Maintenance Instructions

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.
CAUTION
INSTALLATION SITE DAMAGE
Failure to follow this caution can result in damage to equip-
ment location site.
Puron (R-410A) refrigerant contains polyolester (POE) oil
that can damage the roof membrane. Caution should be tak-
en to prevent POE oil from spilling onto the roof surface.
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.
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 re-
move the compressor's tube plugs until ready to insert the unit
suction and discharge tube ends.

Compressor Rotation

CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution can result in premature wear
and damage to equipment.
Scroll compressors can only compress refrigerant if rotat-
ing 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.
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 deter-
mine whether or not compressor is rotating in the proper direc-
tion:
1. Connect service gages to suction and discharge pressure
fittings.
2. Energize the compressor. 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 dis-
charge pressure does not rise to normal levels, the evapo-
rator fan is probably also rotating in the wrong direction.
3. Turn off power to the unit.
4. Reverse any two of the three unit power leads.
5. Reapply electrical power to the compressor. The suction
pressure should drop and the discharge pressure should
rise which is normal for scroll compressors on start-up.
6. Replace compressor if suction/discharge pressures are not
within specifications for the specific compressor.
The suction and discharge pressure levels should now move to
their normal start-up levels.

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 HAZARD
Failure to follow this CAUTION can result in premature
wear and damage to equipment.
Do not install a suction-line filter drier in liquid line. A liq-
uid-line filter drier designed for use with Puron refrigerant
is required on every unit.

Outdoor Fan Location

1. Shut off unit power supply. Apply lockout/tagout proce-
dures.
2. Remove condenser-fan assembly (grille, motor, and fan).
3. Loosen fan hub setscrews.
4. Adjust fan height as shown in Fig. 29.
5. Tighten setscrews to 84 in-lbs (9.5 Nm).
6. Replace condenser-fan assembly.
Fig. 29 — Condenser Fan Adjustment

Troubleshooting Cooling System

Refer to Table 6 for additional troubleshooting topics.
17
CAUTION
0.14 in. + 0.0 / -0.03
CONDUIT