Installation Manual
4
remaining ushing agent from the lines or indoor coil. Re-
placement of indoor coil is recommended.
NOTE: If using existing indoor coil and changing
refrigerant types, ensure the indoor coil and metering
device are compatible with the type of refrigerant being
used. If new indoor coil is required check spec sheet or
AHRI for approved coil. If system is being replaced due to
compressor electrical failure, assume acid is in system.
Refer to Service Procedure S-115 Compressor Burnout
in service manual for clean-up procedure.
BuryIng refrIgerant lIneS
If burying refrigerant lines can not be avoided, use the fol-
lowing checklist.
1. Insulate liquid and suction lines separately.
2. Enclose all underground portions of the refrigerant
lines in waterproof material (conduit or pipe) sealing
the ends where tubing enters/exits the enclosure.
3. If the lines must pass under or through a concrete slab,
ensure lines are adequately protected and sealed.
refrIgerant lIne connectIonS
IMPORTANT
To avoid overheating the service valve, TXV valve, or
lter drier while brazing, wrap the component with
a wet rag, or use a thermal heat trap compound.
Be sure to follow the manufacturer’s instruction
when using the heat trap compound. Note: Remove
Schrader valves from service valves before brazing
tubes to the valves. Use a brazing alloy of 2%
minimum silver content. Do not use ux.
Torch heat required to braze tubes of various sizes is
proportional to the size of the tube. Tubes of smaller
size require less heat to bring the tube to brazing
temperature before adding brazing alloy. Applying
too much heat to any tube can melt the tube. Service
personnel must use the appropriate heat level for the
size of the tube being brazed. NOTE: The use of a
heat shield when brazing is recommended to avoid
burning the serial plate or the nish on the unit.
1. The ends of the refrigerant lines must be cut square,
deburred, cleaned, and be round and free from nicks
or dents. Any other condition increases the chance of
a refrigerant leak.
2. “Sweep” the refrigerant line with nitrogen or inert gas
during brazing to prevent the formation of copper-
oxide inside the refrigerant lines. The POE oils used
in R-410A applications will clean any copper-oxide
present from the inside of the refrigerant lines and
spread it throughout the system. This may cause a
blockage or failure of the metering device.
3. After brazing, quench the joints with water or a wet
cloth to prevent overheating of the service valve.
4. Ensure the lter drier paint nish is intact after brazing.
If the paint of the steel lter drier has been burned or
chipped, repaint or treat with a rust preventative. This
is especially important on suction line lter driers which
are continually wet when the unit is operating.
NOTE: Be careful not to kink or dent refrigerant lines. Kinked
or dented lines will cause poor performance or compressor
damage.
Do NOT make nal refrigerant line connection until plugs
are removed from refrigerant tubing.
NOTE: Before brazing, verify indoor TXV is correct for R410A
and proper size.
leak teStIng (nItrogen or nIrtogen-traced)
T
O
AVOID
THE
RISK
OF
FIRE
OR
EXPLOSION
,
NEVER
USE
OXYGEN
,
HIGH
PRESSURE
AIR
OR
FLAMMABLE
GASES
FOR
LEAK
TESTING
OF
A
REFRIGERATION
SYSTEM
.
WARNING
T
O
AVOID
POSSIBLE
EXPLOSION
,
THE
LINE
FROM
THE
NITROGEN
CYLINDER
MUST
INCLUDE
A
PRESSURE
REGULATOR
AND
A
PRESSURE
RELIEF
VALVE
. T
HE
PRESSURE
RELIEF
VALVE
MUST
BE
SET
TO
OPEN
AT
NO
MORE
THAN
150
PSIG
.
WARNING
Pressure test the system using dry nitrogen and soapy water
to locate leaks. If you wish to use a leak detector, charge the
system to 10 psi using the appropriate refrigerant then use
nitrogen to nish charging the system to working pressure
then apply the detector to suspect areas. If leaks are found,
repair them. After repair, repeat the pressure test. If no leaks
exist, proceed to system evacuation.
SyStem evacuatIon
Condensing unit liquid and suction valves are closed to con-
tain the charge within the unit. The unit is shipped with the
valve stems closed and caps installed. Do not open valves
until the system is evacuated.