GVZC20 Installation Manual
7
IMPORTANT
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. Purge with nitrogen at 2 to 3 psig during brazing
to prevent the formation of copper-oxide inside
the refrigerant lines. The FVC 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. A bi-ow lter drier is shipped with the unit as a
separate component and must be brazed on by the
installer on-site. Ensure the bi-ow 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.
The recommended location of the lter drier is before the
expansion device at the indoor unit.
Do NOT make nal refrigerant line connection until plugs
are removed from refrigerant tubing.
WARNING
TO AVOID THE RISK OF FIRE OR EXPLOSION, NEVER USE OXYGEN,
HIGH PRESSURE AIR OR FLAMMABLE GASES FOR LEAK TESTING OF A
REFRIGERATION SYSTEM.
WARNING
TO AVOID POSSIBLE EXPLOSION, THE LINE FROM THE NITROGEN
CYLINDER MUST INCLUDE A PRESSURE REGULATOR AND A PRESSURE
RELIEF VALVE. THE PRESSURE RELIEF VALVE MUST BE SET TO OPEN AT
NO MORE THAN 450 PSIG.
To locate leaks, pressure test the system using dry
nitrogen or leak detector uid per the manufacturer’s
recommendation. 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
Start-up Procedure.
Best practices dictate system should be pressure tested
at 450 PSIG with nitrogen for a minimum 4 hours. Follow
the procedure outlined below to test system. If leaks are
found, repair them. After repair, repeat the leak pressure
test described above. If no leaks exist, proceed to system
evacuation and charging.
SYSTEM PRESSURE TESTING
Once all of the refrigerant line connections are completed.
Perform a 3-step nitrogen pressure test.
1. Pressurize the system with nitrogen to 150 PSIG and
hold for 3 minutes. If any pressure drops occur, locate
and repair leaks and repeat step 1.
2. Pressurize the system with nitrogen to 325 PSIG and
hold for 5 minutes. If any pressure drops occur, locate
and repair leaks and repeat step 1.
3. Pressurize the system with nitrogen to 450 PSIG and
hold for 4 hours. If any pressure drops occur, locate
and repair leaks and repeat step 1.
V
IOLATION
OF
EPA
REGULATIONS
MAY
RESULT
IN
FINES
OR
OTHER
PENALTIES
.
NOTICE
ALL UNITS SHOULD HAVE A HIGH VOLTAGE POWER SUPPLY CONNECTED
2
HOURS PRIOR TO STARTUP.
NOTICE