Carrier 38AK024-044 - Manual (Page 3)

Placing Unit — There must be 4 ft (1220 mm) for service
and for unrestricted airflow on all sides of unit, and a
minimum of 8 ft (2440 mm) clear air space above unit. For
multiple units, allow 8 ft separation between units for
airflow and service.
Mounting Unit — When unit is in proper location, use of
mounting holes in base rails is recommended for securing
unit to supporting structure, or for mounting unit on
vibration isolators if required. Fasteners for mounting unit
are field supplied. Be sure to mount unit level to ensure
proper oil return to compressors.
Compressor Mounting — As shipped, compressor is
held down by 4 bolts. After unit is installed loosen each bolt
until the snubber washer can be moved with finger pressure.
See Fig. 3.
Single Pumpout Control — All units are factory wired
to operate on single pumpout control. A factory-supplied
liquid line solenoid valve must be installed in the liquid line
ahead of the indoor coil. See Fig. 5. Wires from solenoid
valve must be in conduit, and a ground wire must be
provided to comply with codes.
A WARNING
Failure to properly install liquid line solenoid at the
indoor unit as described, without Carrier author­
ization, may VOID warranty.
If unit is used with a chiller, wiring modifications may be
required.
Filter Drier And Moisture Indicator — Every unit
should have a filter drier and a sight glass (moisture
indicator) field installed. Select the filter drier for maximum
unit Capacity and minimum pressure drop. Figure 5 shows
recommended locations of filter drier(s) and sight glass.
Complete the refrigerant piping from the evaporator to the
condenser before opening the liquid and suction lines at the
condensing unit. One filter drier may be installed at location
A in Fig. 5, or 2 filter driers may be installed at locations B.
INSTALLATION
Refrigerant Piping Connections — Line sizes depend
on length of piping required between condensing unit and
evaporator. See Table 2. It is important to consider liquid
lift and compressor oil return. Refer to Part 3 of Carrier
System Design Manual for line sizing information, and
Fig. 4 for recommended piping details.
NOTES:
1 Suction line is connected to coil on same side as the entering air.
2 For coils having only one section, use upper section piping; for coiis
having 2 sections, use upper and middle section piping
3 Lower section is first on and last off.
4 For more complete piping information, refer to Carrier System
Design Manual, Part 3
Fig. 4 — Suction Line Piping to Unit
with 3 Section Coil Split
FACTORY SUPPLIED
SOLENOID VALVE FIELD SUPPLIED
CAPACITY CONTROL
Fig. 5 — Liquid Line Solenoid Valve,
Filter Drier(s) and Sight Glass Locations
Receiver — No receiver is provided with the unit; it is
recommended that one not be used.
Piping Procedure — Do not remove run-around pipe
from suction and liquid line stubs until piping connections are
ready to be made. Pass nitrogen or other inert gas through
piping while brazing, to prevent formation of copper oxide.
Install field-supplied thermostatic expansion valve in
liquid line ahead of each evaporator section. For 2-step
cooling,
the fleld-supplkd solenoid used must be wired to be
opened by control from a 2-step thermostat
For example: 2 solenoids may be used with 3 TXVs —one
of the solenoids serving a liquid line feeding 2 of the TXVs.