Gree GMV MTAC VRF Series, Service Manual

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Gree GMV MTAC VRF for North America
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5.2 Fill and Charge Refrigerant
5.2.1 Filling Procedure of Regrigerant
Refrigerant quantity of outdoor unit before delivery:
Model GMV-12WP/A-T(U)
Refrigerant Qty (kg/oz) 0.8 (28.2)
(1) The refrigerant amount charged before delivery doesn’t include the amount that needs to be added to indoor
units and the connection pipeline.
(2) Length of connection pipe is decided on site. Therefore the amount of additional refrigerant shall be decided on
site according to the dimension and length of field-installed liquid pipe.
(3) Record the amount of additional refrigerant for convenience of after-sales service.
Calculation of the amount of additional refrigerant see part of 6.2.2 Refrigerant Adding.
5.3.2 Operation Procedure for Adding Refrigerant
(1) Put the charging tank on the weightometer, record the reading and then calculate the
data after charging refrigerant.
(2) Use charging conduct pipe to connect the double-ended manometer with governing valve
and liquid-charging tank to the detection head of gas valve and liquid valve. Before
connection, please release some refrigerant and then drain out the air inside the charging
conduct pipe.
(3) Confirm that the gas valve and liquid valve for outdoor unit is at off status.
(4) When the unit hasn’t been turned on, open the governing valve for the liquid-charging
tank and then charge refrigerant from gas pipe and liquid pipe at the same time.
(5) Obeserve the data weightometer, close the valve after it is reached to requirement and
then close the valve for liquid-charging tank.
(6) If the refrigerant can’t be added completely, add it when turning on the unit. Charge
refrigerant from the detection joint of cooling gas pipe or detection joint of gas vavle.
5.2.3 Notice for Filling Refrigerant
(1) Calculate the section and length of cooling liquid pipe preciously for the precision
refrigerant-charing volume.
(2) Measure the additional refrigerant volume preciously.
(3) Invert to charge the R410A for ensuting the liquid-charging.
(4) When the temperature is low, heat the liquid-storage tank with hot water or hot wind for
helping refrigerant-charging. However, prohibit use flame to heat the liquid-storage tank
directly. Otherwise, it may cuase personal injury or property damage due to explosion.
5.3 Airtightness Test
5.3.1 Importance of Airtightness Rest
The airtightness of VRF system is the leak tightness of the pipeline for refrigerant, which the
guarantee for safe and reliable operation. The leakage of refrigerant may affect the operation of air