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38
Compressor Protection
COMPRESSOR OVER-TEMPERATURE PROTECTION
(IP)
A thermostat installed on the compressor motor winding
reacts to excessively high winding temperatures and shuts off
the compressor.
CRANKCASE HEATER
The heater minimizes absorption of liquid refrigerant by
oil in the crankcase during brief or extended shutdown peri-
ods. The heater is wired to cycle with the compressor; the
heater is off when compressor is running, and on when com-
pressor is off.
The crankcase heater will operate as long as the power cir-
cuit is energized. The main disconnect must be on to energize
the crankcase heater.
ADVANCED SCROLL TEMPERATURE PROTECTION
(ASTP)
See “Advanced Scroll Temperature Protection (ASTP)” on
page 24.
LOW-PRESSURE SWITCH
The 38AU low-pressure switch is stem-mounted on the
suction line. Switches are all fixed, non-adjustable type.
HIGH-PRESSURE SWITCH
The high-pressure switch is stem mounted on the dis-
charge line. The switch is a fixed, non-adjustable type.
OUTDOOR FANS
Each fan is supported by a formed-wire mount bolted to
the fan deck and covered with a wire guard. Fan motors have
permanently lubricated bearings.
1. Shut off unit power supply. Install lockout tag.
2. Remove outdoor fan assembly (grille, motor, and fan).
3. Loosen fan hub setscrews.
4. Adjust fan height as shown in Fig. 41.
5. Tighten setscrews to 84 in.-lbs (949 N-cm).
6. Replace outdoor fan assembly.
Fig. 41 — Outdoor Fan Blade Position
LUBRICATION
Fan Motors
The fan motors have sealed bearings. No provisions are
made for lubrication.
Compressor
The compressor has its own oil supply. Loss of oil due to a
leak in the system should be the only reason for adding oil af-
ter the system has been in operation.
ROUTINE CLEANING OF ROUND-TUBE PLATE FIN
(RTPF) COILS
Periodic cleaning with Totaline
®
environmentally sound
coil cleaner is essential to extend the life of RTPF coils. This
cleaner is available from Carrier Replacement parts division
as part number P902-0301 for a one gallon container, and part
number P902-0305 for a 5 gallon container. It is recommend-
ed that all RTPF coils be cleaned with the Totaline environ-
mentally sound coil cleaner as described below.
Coil cleaning should be part of the unit’s regularly sched-
uled maintenance procedures to ensure long life of the coil.
Failure to clean the coils may result in reduced durability in
the environment.
Avoid the use of:
• coil brighteners
• acid cleaning prior to painting
• high pressure washers
• poor quality water for cleaning
Totaline environmentally sound coil cleaner is non-flam-
mable, hypoallergenic, non-bacterial, and a USDA accepted
biodegradable agent that will not harm the coil or surround-
ing components such as electrical wiring, painted metal sur-
faces, or insulation. Use of non-recommended coil cleaners is
strongly discouraged since coil and unit durability could be
affected.
TOTALINE ENVIRONMENTALLY SOUND COIL
CLEANER APPLICATION EQUIPMENT
• 2
1
/
2
gallon garden sprayer
• water rinse with low velocity spray nozzle
Totaline Environmentally Sound Coil Cleaner Application
Instructions:
NOTE: Proper eye protection such as safety glasses is recom-
mended during mixing and application.
1. Turn off unit power.
2. Remove screws holding rear corner post and top cover in
place. Pivot top cover up 12 to 18 inches (305 to 457
mm) and support with a rigid support. See Fig. 42.
IMPORTANT: Never open any switch or disconnect that
energizes the crankcase heater unless unit is being serviced
or is to be shut down for a prolonged period. After a pro-
longed shutdown on a service job, energize the crankcase
heater for 24 hours before starting the compressor.
3.6 mm +0/0/-0.8
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in corrosion and
damage to the unit.
Harsh chemicals, household bleach or acid or basic cleaners
should not be used to clean outdoor or indoor coils or any
kind. These cleaners can be very difficult to rinse out of the
coil and can accelerate corrosion at the fin/tube interface
where dissimilar materials are in contact. If there is dirt
below the surface of the coil use the Totaline environmen-
tally sound coil cleaner as described above.
IMPORTANT: High velocity water from a pressure
washer, garden hose, or compressed air should never be
used to clean a coil. The force of the water or air jet will
bend the fin edges and increase airside pressure drop,
resulting in reduced unit performance.
Summary of Contents for Gemini 38AU07 Series
Page 5: ...5 Fig 3 38AUD Z 07 14 Base Unit Dimensions ...
Page 19: ...19 Fig 17 Typical Single Circuit Single Stage 38AUZ Wiring Diagrams ...
Page 20: ...20 Fig 18 Typical Single Circuit Two Stage 38AUZ Wiring Diagram ...
Page 21: ...21 Fig 19 Typical Dual Circuit Two Stage 38AUD Wiring Diagram ...
Page 30: ...30 Fig 30 38AUZD E08 Charging Chart RTPF 7 5 Ton Dual Stage Charging Chart R 410A Refrigerant ...
Page 48: ......
Page 49: ......