Evacuation - LG ARND203DCR4 Installation Manual

Figure 32: Leak / Pressure Test for system designed for DOAS
Note:
Farthest slave outdoor unit is the slave outdoor unit installed farthest away from the refrigerant piping system / DOAS unit

Evacuation

After the leak / pressure check is complete, perform a
Triple Evacuation with the entire system. Evacuation
must be performed through the Schrader ports on the
outdoor unit service ports.
Note:
For faster evacuation, the Schrader core can be removed, and
an auxiliary service port can used. Make sure to re-install the
original Schrader core before operating the system.
For Heat Recovery systems, evacuate through all three
(3) hot gas line (high pressure vapor), liquid line, and
suction (low pressure vapor) refrigerant lines.
The outdoor unit service valves must remain closed and
the stem head access caps tight. Do not open the
outdoor unit service valves and release the factory
refrigerant charge until the LG trained commissioner
authorizes to do so. The system must be left in vacuum
until the LG trained commissioner verifies the quality of
the evacuation.
Any field-installed ball valves in the refrigerant system (if
used) must be open to ensure all piping is free and clear
for evacuation on all piping and connected indoor units /
heat recovery units.
Note:
•
⊘
Do not apply power to the units before performing a
system leak test. There is a possibility that the EEV valves
will close and isolate sections of the piping system, making
the leak test inconclusive. Contact your LG Applied Rep or
service technician for the procedure to reopen the EEV
valves before the leak test ONLY if the power has been
applied
•
For multi-frame outdoor units, connect the vacuum pump /
manifold to the service port Schrader ports (or core) to only
one outdoor unit, preferably the slave outdoor unit that is
installed farthest away from the refrigerant piping system
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Due to our policy of continuous product innovation, some specifications may change without notification.
and connected indoor units / heat recovery units.
•
Use only a vacuum pump that can reach 500 microns,
vacuum rated hoses or copper tubing, and a leak-free
gauge manifold set
•
Use only new vacuum pump oil from a properly sealed
(unopened) container, and change oil in pump before
EVERY use.
•
Subsequent oil changes will be necessary after several
hours of continuous operation; have extra oil on hand.
•
Use a quality micron gauge in good operating order and
install as far away from pump as possible
Evacuation Procedure Steps
1. If this procedure is performed shortly after the leak /
pressure test, the caps and cores on the Schrader
ports must have already been removed, and the
manifold must already be connected. If the
procedure was not performed shortly after the leak /
pressure test, make sure to remove the caps and
cores on the Schrader ports. Verify that the service
valves on the outdoor unit are closed, and the stem
head access caps are tight.
Note:
Connect the vacuum pump to the gauge manifold and hoses.
Once the vacuum pump is first operated, if hoses, manifold,
and vacuum valves are leak free (and oil is no moisture laden),
the gauge must read <100 microns within on (1) minute.
2. Connect the gauge manifold along with the vacuum
pump to the Schrader ports (with core removed)
using vacuum hoses. Open the gauge manifold and
the vacuum pump valves
3. Operate the vacuum pump and evacuate the system
to the 2,000 micron level. Isolate the pump by closing
the manifold gauges and the vacuum pump valve,
and then watch the micron level. Micron level could
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