Gree GMV MTAC VRF Series, Руководство по обслуживанию

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Gree GMV MTAC VRF for North America
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conditioner seriously, or even damage compressor and then lead to breakdown of system.
Therefore, it needs to perform the airtightness test. If the there’s gas leakage after the system is
installed completely, because the indoor ceiling decoration are all finished, it’s will be very difficult
to find out the leakage point. Thus, the airtightness test of the system must be finished before
finishing indoor decoration.
5.3.2 Operation Procedure for the Airtightness Test
Before ex-factory, cut-off valve for gas pipe and liquid pipe of outdoor unit is turned off. Please
confirm that before operation.
Before testm please smear a little corresponding lubricant oil at Blanking plug. and pipe
terminal, and use two wrenches for fixing Blanking plug.
Do not allow to connect the pipeline of outdoor unit for test during airtightness test.
The system test pressure for R410A is 4.15MPa (3.0MPa for R22 refrigerant system).
Nitrogen must be used as the medium for the airtightness test and the nitrogen should be dry.
Increase pressure slowly for three steps:
Step 1: Increase pressure slowly to 0.5MPa, stop for 5min and then check the gas leakage.
Big leakage may be found out;
Step 2: Increase pressure slowly to 1.5MPa, stop for 5min to check the airtightness. Small
leakage may be found out;
Step 3: Increase pressure slowly to 4.15MPa for R410A slowly (3.0MPa for R22 refrigerant
system), stop for 5min and perform the strength test. Minor leakage or sand hole may be found.
Increase pressure to test pressurem, keep it for 24h and observe whether the pressure is
decreasing. If not, the pressure is qualified.
5.3.3 Cautions
(1) The test manometer range for R410A should be 4.5MPa above (3.5MPa above for R22
refrigerant system).
(2) Record the data on manometerk, ambient temperature and test time at the same time;
(3) Pressure modification: when temperature changes 1°C, the temperature will change
0.01MPa correspondingly.
(4) Pressure should be kept the same.
(5) If it needs to keep pressure for a long time, decrease the pressire lower than 0.55MPa pr
below. Long-time high pressure can lead to leakage at the welding position, which may
cause riskl.
(6) Before the airtightness for the pipeline of refrigerant is finished, do not allow to insulate
and bundle the welding positions and connection position of bellmouth of indoor unit.
Add pressure from gas pipe and
liquid pipeat the same time
NOTICE! Before airtightness test, all welding lines can’t be insulated and bundled.