16
Compressor Rotation
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
direction:
1. Connect service gages to suction and discharge pressure
fittings.
2. Energize the compressor.
3. The suction pressure should drop and the discharge pres
-
sure 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, the evaporator fan is prob
-
ably also rotating in the wrong direction.
4. Turn off power to the unit.
5. Reverse any two of the three unit power leads.
6. 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.
7. 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 whenever refrigerant system is exposed to atmo
-
sphere. Only use factory specified liquid-line filter driers with
working pressures no less than 650 psig (4482 kPa).
Condenser-Fan Adjustment
1. Shut off unit power supply. Install lockout tag.
2. Remove condenser-fan assembly (grille, motor, and fan).
See Fig. 26.
3. Loosen fan hub setscrews.
4. Adjust fan height by pushing fan until it stops on the fan
shaft.
5. Tighten set screw to 60 in.-lb (6.78 Nm).
6. Replace condenser-fan assembly. When replacing the
condenser-fan assembly follow the screw pattern sequence
shown in Fig. 27. The screws must be replaced in the
sequence shown in the figure.
Fig. 26 — Condenser Fan Adjustment
Fig. 27 — Condenser-Fan Assembly — Screw Pattern Sequence
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
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
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 R-410A
refrigerant is required on every unit.
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5
NO SCREW
(Blank Tab)