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Liquid And Suction Line Service Valve
(Valve Open)
Schrader
valve
service
port
service port
cap
insert hex
wrench here
to indoor coil
to outdoor coil
stem cap
Schrader valve open
to line set when valve
is closed (front seated)
service
port
service
port cap
stem cap
insert hex
wrench here
Liquid And Suction Line Service Valve
(Valve Closed)
(valve front seated)
to outdoor coil
to indoor coil
FIGURE 4
SUCTION LINE (BALL TYPE) SERVICE VALVE
VALVE CORE
SERVICE PORT
STEM CAP
STEM
USE ADJUSTABLE WRENCH
ROTATE STEM CLOCKWISE 90
TO CLOSE
ROTATE STEM COUNTERCLOCKWISE 90
TO OPEN
BALL
(SHOWN OPEN)
FROM INDOOR COIL
TO COMPRESSOR
SERVICE PORT
CAP
FIGURE 5
III-START-UP
The following is a general procedure and does not apply
to all thermostat control systems. Refer to sequence of
operation in this manual for more information.
IMPORTANT
Crankcase heaters must be energized for 24 hours before
attempting to start compressors. Set thermostat so there
is no compressor demand before closing disconnect
switch. Attempting to start compressors during the 24-
hour warm-up period could result in damage or failed
compressors.
1 - Set fan switch to AUTO or ON and move the system
selection switch to COOL. Adjust the thermostat to a
setting far enough below room temperature to bring
on compressors. Compressors will start and cycle
on demand from the thermostat (allowing for unit
and thermostat time delays).
2 - Each circuit is eld charged with HCFC-410A
refrigerant.
3 - Refer to Charging section for proper method of
checking and charging the system.
IMPORTANT
Three-phase scroll compressors must be phased
sequentially to ensure correct compressor rotation
and operation. At compressor start-up, a rise in
discharge and drop in suction pressures indicate proper
compressor phasing and operation. If discharge and
suctions pressures do not perform normally, follow the
steps below to correctly phase in the unit.
1 - Disconnect power to the unit.
2 - Reverse any two eld power leads (L1 and L3
preferred) to the unit.
3 - Reapply power to the unit.
Discharge and suction pressures should operate at their
normal start-up ranges.
NOTE - Compressor noise level will be signicantly high-
er when phasing is incorrect and the unit will not provide
cooling when compressor is operating backwards. Con-
tinued backward operation will cause the compressor to
cycle on internal protector.
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