Vacuum Drying and Leakage Checking
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7. Vacuum Drying and Leakage Checking
4.1 Purpose of vacuum drying
Eliminating moisture in system to prevent the phenomena of ice-blockage and copper oxidation.
Ice-blockage shall cause abnormal operation of system, while copper oxide shall damage compressor.
Eliminating the non-condensable gas (air) in system to prevent the components oxidizing, pressure
fluctuation and bad heat exchange during the operation of system.
4.2 Selection of vacuum pump
The ultimate vacuum degree of vacuum pump shall be -756mmHg or above.
Precision of vacuum pump shall reach 0.02mmHg or above.
4.3 Operation procedure for vacuum drying
Due to different construction environment, two kinds of vacuum drying ways could be chosen, namely
ordinary vacuum drying and special vacuum drying.
7.3.1 Ordinary vacuum drying
1. When conduct first vacuum drying, connect pressure gauge to the infusing mouth of gas pipe and liquid
pipe, and keep vacuum pump running for 1hour (vacuum degree of vacuum pump shall be reached
-755mmHg).
2 If the vacuum degree of vacuum pump could not reach -755mmHg after 1 hour of drying, it indicates
that there is moisture or leakage in pipeline system and need to go on with drying for half an hour.
3 If the vacuum degree of vacuum pump still could not reach -755mmHg after 1.5 hours of drying, check
whether there is leakage source.
4 Leakage test: After the vacuum degree reaches -755mmHg, stop vacuum drying and keep the pressure
for 1 hour. If the indicator of vacuum gauge does not go up, it is qualified. If going up, it indicates that
there is moisture or leak source.
7.3.2 Special vacuum drying
The special vacuum drying method shall be adopted when:
1. Finding moisture during flushing refrigerant pipe.
2. Conducting construction on rainy day, because rain water might penetrated into pipeline.
3. Construction period is long, and rain water might penetrated into pipeline.
4. Rain water might penetrate into pipeline during construction.
Procedures of special vacuum drying are as follows:
1. Vacuum drying for 1 hour.
2. Vacuum damage, filling nitrogen to reach 0.5Kgf/cm2 .
Because nitrogen is dry gas, vacuum damage could achieve the effect of v acuum drying, but this
method could not achieve drying thoroughly when there is too much moisture. Therefore, special
attention shall be drawn to prevent the entering of water and the formation of condensate water.
3. Vacuum drying again for half an hour.
If the pressure reached -755mmHg, start to pressure leakage test. If it cannot reached the value,
repeat vacuum damage and vacuum drying again for 1 hour.
4 Leakage test: After the vacuum degree reaches -755mmHg, stop vacuum drying and keep the pressure
for 1 hour. If the indicator of vacuum gauge does not go up, it is qualified. If going up, it indicates that
there is moisture or leak source.
Summary of Contents for Super DC Series
Page 1: ...Contents i Energy Related Products SUPER DC INVERTER SERIES Service Manual 2017...
Page 14: ...Service Space Indoor Units 12 3 Service Space 1000mm 1000mm 1000mm 1000m m Chart 3...
Page 17: ...Air Velocity Distributions Reference Data Indoor Units 15 30 42K Cooling Heating...
Page 18: ...Air Velocity Distributions Reference Data Indoor Units 16 48 55K Cooling Heating...
Page 23: ...Field Wiring Indoor Units 21 10 Field Wiring...
Page 30: ...Wiring Diagrams Indoor Units 28 4 Wiring Diagrams MTBU 12HWFN1 QRD0W MTB 18HWFN1 QRD0...
Page 32: ...Static Pressure Indoor Units 30 5 Static Pressure MTBU 12HWFN1 QRD0W MTB 18HWFN1 QRD0...
Page 33: ...Static Pressure Indoor Units 31 MTB 24HWFN1 QRD0 MTB 30HWFN1 QRD0...
Page 45: ...Features Indoor Units 43...
Page 53: ...Field Wiring Indoor Units 51 9 Field Wiring...
Page 57: ...Service Space Indoor Units 55 3 Service Space...
Page 67: ...Field Wiring Indoor Units 65 10 Field Wiring...
Page 70: ...Features Indoor Units 68...
Page 72: ...Service Space Indoor Units 70 3 Service Space...
Page 73: ...Wiring Diagrams Indoor Units 71 4 Wiring Diagrams MCA3U 12HRFN1 QRD0W MCA3 18HRFN1 QRD0...
Page 77: ...Field Wiring Indoor Units 75 10 Field Wiring MCA3U 12HRFN1 QRD0W MCA3 18HRFN1 QRD0...
Page 81: ...Features Console Type 79 1 7 Active carbon filter is standard...
Page 83: ...Console Type Console Type 81 3 Service Space...
Page 84: ...Console Type Console Type 82 4 Wiring Diagrams MFAU 12HRFN1 QRC8W MFA 16HRFN1 QRC8W...
Page 89: ...Console Type Console Type 87 10 Field Wiring...
Page 93: ...Service Space M Floor standing Type 91 3 Service Space...
Page 95: ...Wiring Diagrams M Floor standing Type 93 MFM 55ARFN1 RRD0...
Page 101: ...Field Wiring M Floor standing Type 99 MFM 55ARFN1 RRD0...
Page 105: ...Service Space GAFloor standing Type 103 3 Service Space...
Page 106: ...Wiring Diagrams GAFloor standing Type 104 4 Wiring Diagrams MFGA 55ARFN1 RRD0 B...
Page 112: ...Field Wiring GAFloor standing Type 110 10 Field Wiring...
Page 115: ...Dimensions Outdoor Units 113 Model KBtu h Unit mm W D H W1 A B 48 55 952 415 1333 1045 634 404...
Page 117: ...Wiring Diagrams Outdoor Units 115 3 Wiring Diagrams MOB30U 12HFN1 QRD0W MOB30U 16HFN1 QRC8W...
Page 118: ...Wiring Diagrams Outdoor Units 116 MOB30U 18HFN1 QRD0 MOCA30U 24HFN1 QRD0 MOD30U 30HFN1 QRD0...
Page 119: ...Wiring Diagrams Outdoor Units 117 MOD30U 36HFN1 QRD0 MOD30U 42HFN1 QRD0...
Page 120: ...Wiring Diagrams Outdoor Units 118 MOD30U 36HFN1 RRD0 MOD30U 42HFN1 RRD0...
Page 121: ...Wiring Diagrams Outdoor Units 119 MOE30U 48HFN1 QRD0 MOE30U 48HFN1 RRD0 MOE30U 55HFN1 RRD0...
Page 154: ...Refrigerantpipe installation Installation 152...
Page 179: ...Troubleshooting Electrical Control System 177 2 1 8 Display board of GA floor standing...