Gree MULTI VRF SYSTEM II GMV-120WL/A-T User Manual

80
DC Inverter Multi VRF System II
Service Manual
Length 10m 10m 10m 10m
Length of liquid pipe:
φ9.52:A+B+C+a=20+10+5+10=45m
φ6.35:D+b+c+d=5+10+10+10=35m
L= (9.52 length of liquid pipe)×1+(6.4 length of liquid pipe) ×0.4
= 45×1+35×0.4=59m
LA=L-50=59-50=9 m
R=LA×54 =9×54=486 g
Additional volume of refrigerant R=LA×54 =9×54=486 g
b.Operation procedure for adding refrigerant
b1.Put the charging tank on the weightometer, record the reading and then calculate the data after charging refrigerant;
b2.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;
b3.Conrm that the gas valve and liquid valve for outdoor unit is at off status;
b4.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.
b5.Obeserve the data weightometer, close the valve after it is reached to requirement and then close the valve for liquid-charging tank;
b6.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.
c .Notice for lling refrigerant
c1.Calculate the section and length of cooling liquid pipe preciously for the precision refrigerant-charing volume.
c2Measure the additional refrigerant volume preciously;
c3.R410AInvert to charge the R410A for ensuting the liquid-charging;
c4. When the temperature is low, heat the liquid-storage tank with hot water or hot wind for helping refrigerant-charging. However,
prohibit use ame to heat the liquid-storage tank directly. Otherwise, it may cuase personal injury or property damage due to explosion.
6.3 Airtightness test
6.3.1 Importance of airtightness test
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 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 nished, it’s will be very difcult to nd out the leakage point. Thus, the airtightness test of the system must
be nished before nishing indoor decoration.
6.3.2 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 conrm 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 qualied.
6.3.3 Cautions
a .The test manometer range for R410A should be 4.5MPa above (3.5MPa above for R22 refrigerant system);
b .Record the data on manometerk, ambient temperature and test time at the same time;
c .Pressure modication: when temperature changes 1
o
C, the temperature will change 0.01MPa correspondingly.
d Pressure should be kept the same.
e .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.
f . Before the airtightness for the pipeline of refrigerant is nished, do not allow to insulate and bundle the welding positions and
connection position of bellmouth of indoor unit.

Gree MULTI VRF SYSTEM II GMV-120WL/A-T Specifications

General

Brand	Gree
Model	MULTI VRF SYSTEM II GMV-120WL/A-T
Category	Inverter
Language	English