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V−SERVICE AND RECOVERY
WARNING
Polyol ester (POE) oils used with HFC−410A refrig-
erant absorb moisture very quickly. It is very impor-
tant that the refrigerant system be kept closed as
much as possible. DO NOT remove line set caps or
service valve stub caps until you are ready to make
connections.
IMPORTANT − Use recovery machine rated for
R410 refrigerant.
If the XPG20 system must be opened for any kind of ser-
vice, such as compressor or filter drier replacement, you
must take extra precautions to prevent moisture from en-
tering the system. The following steps will help to minimize
the amount of moisture that enters the system during re-
covery of HFC−410A.
1 − Use a regulator−equipped nitrogen cylinder to break
the system vacuum. Do not exceed 5 psi. The dry ni-
trogen will fill the system, and will help purge any mois-
ture.
2 − Remove the faulty component and quickly seal the
system (using tape or some other means) to prevent
additional moisture from entering the system.
3 − Do not remove the tape until you are ready to install
new component. Quickly install the replacement com-
ponent.
4 − Evacuate the system to remove any moisture and oth-
er non−condensables.
The XPG20 system MUST be checked for moisture
any time the sealed system is opened.
Any moisture not absorbed by the polyol ester oil can be re-
moved by triple evacuation. Moisture that has been ab-
sorbed by the compressor oil can be removed by replacing
the filter drier.
IMPORTANT
Evacuation of system only will not remove mois-
ture from oil. Filter drier must be replaced to elimi-
nate moisture from POE oil.
VI−MAINTENANCE
WARNING
Electric shock hazard. Can cause inju-
ry or death. Before attempting to per-
form any service or maintenance, turn
the electrical power to unit OFF at dis-
connect switch(es). Unit may have
multiple power supplies.
Maintenance and service must be performed by a quali-
fied installer or service agency. At the beginning of each
cooling or heating season, the system should be checked
as follows:
Outdoor Unit
1 − Clean and inspect outdoor coil (may be flushed with a
water hose). Ensure power is off before cleaning.
2 − Outdoor unit fan motor is prelubricated and sealed. No
further lubrication is needed.
3 − Visually inspect all connecting lines, joints and coils for
evidence of oil leaks.
4 − Check all wiring for loose connections.
5 − Check for correct voltage at unit (unit operating).
6 − Check amp−draw on outdoor fan motor and compres-
sor (high and low capacity).
7 − Inspect drain holes in coil compartment base and
clean if necessary.
NOTE − If owner complains of insufficient cooling, the unit
should be gauged and refrigerant charge checked. Refer to
section on refrigerant charging in this instruction.
VII−BRAZING
Before brazing remove access panels and any piping pan-
els to avoid burning off paint. Be aware of any components
ie, service valves, reversing valve, pressure switches that
may be damaged due to brazing heat.
When making line set connections, use 1 to 2 psig dry nitro-
gen to purge the refrigerant piping. This will help to prevent
oxidation into the system.
WARNING
Danger of explosion: Can cause equipment damage,
injury or death. When using a high pressure gas
such as dry nitrogen to pressurize a refrigeration or
air conditioning system, use a regulator that can
control the pressure down to 1 or 2 psig (6.9 to 13.8
kPa).
1 − .Cut ends of copper square (free from nicks or dents).
Debur the ends. The pipe must remain round, do not
pinch end of line.
2 − Wrap wet rag around any components that may be da-
maged.
3 − Use silver alloy brazing rods (5 or 6 percent minimum
silver alloy for copper to copper brazing or 45 percent
silver alloy for copper to brass or copper to steel braz-
ing) which are rated for use with HFC−22 and
HFC−410A refrigerant.
4 − After brazing quench the joints with a wet rag to prevent
possible heat damage to any components.
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