Step 3 - Complete Electrical Connections - Carrier 38AF Series Installation Manual

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INSTALL LIQUID LINE SOLENOID VALVE —
SOLENOID DROP—It is recommended that a
solenoid valve be placed in the main liquid line
(see Fig. 4) between condensing unit (38AE)
and fan coil (40RR). (A liquid line solenoid
valve is required when the liquids line length
exceeds 100-ft [30.5 m] or when the
condensing unit is connected to the chiller
barrel in a built-up chiller system.) This valve
prevents refrigerant migration (which causes oil
dilution) to the compressor during the off cycle
at low outdoors-ambient temperatures. The
solenoid should be wired in parallel with the
compressor contractor coil. This means of
electrical control is referred to as solenoid drop
control.
MAKE PIPING CONNECTIONS —Do not remove run around loop from suction and liquid line stubs in
the compressor compartment until piping connections are ready tube made. Pass nitrogen or other inert
gas through piping while brazing to prevent formation of copper oxide.
Install field supplied thermostatic expansion valve(s) in indoor
section. If 2 thermostatic expansion valves are installed for 2-
step cooling, install field-supplied liquid line solenoid valve
ahead of the second expansion valve.
PROVIDE SAFETY RELIEF — A fusible plug is located on
the compressor crankcase or in the liquid line (Fig. 5). Do not
cap this plug. If local code requires additional safety devices,
install them as directed.
Step 3 – Complete Electrical Connections
POWER WIRING –Unit is factory wired for voltage shown on nameplate. Provide adequate fused
disconnect switch within sight from unit and readily accessible from unit , but out of the reach of children.
Locks witch open (off) to prevent power from being turned on while unit is being serviced. Disconnect
switch. Fuses, and code requirements .
Route power wires through opening in unit end panel to connection in unit control box as shown on unit
label diagram and in Fig 6. Unit must be grounded.
Affix crankcase heater warning sticker to unit disconnects switch.
Main Power Supply Wiring
Product Development Dept.
07/2005
INSTALLLIQUID LINE SOLENOIDVALVE
(OPTIONAL) CAPACITY CONTROLS — If 2-
step cooling is desired, place a solenoid valve
in the location shown in Fig. 4.
Fig.5 - Location of Fusible Plug (38AE)
LEGEND
EQUIP GND – Equipment G round
NEC - National Electrical Code
____ Factory Wiring
----- Field Wiring
Fig. 6 ___ Main Power Supply Wiring
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