Haier AU42NAIBEA User Manual - Page 11

Installation Procedure Refrigerant piping 6. Piping and indoor unit vacuumizing Use vacuum pump to perform vacuumizing. It is strictly forbidden to use the refrigerant to remove the air inside the system. After air tightness test and discharging all the nitrogen, connect the vacuum pump as the following figure shown. Low pressure peizometer High pressure peizometer Indoor Outdoor 3-way valve totally closed (Gas side) V L VH Meter separator Completely tightened Flare part Completely tightened Flare part Discharging valve P Vacuum pump Indoor units Outdoor units 3-way valve totally closed (Liquid side) It shall use the vacuum pump of (lower than -755mmHg)high vacuum degree and large air discharging (over 40l/min). The vacuumizing time depends on the length of the connecting pipe, generally is 1~2 hours. When vacuumizing, it shall be confirmed both gas and liquid side valves are closed. If after 2 hours vacuumizing, it cannot reach the vacuum degree below -755mmHg, it can be vacuumized for other 1 hour. If after 3 hours vacuumizing, it still cannot reach the vacuum degree below -755mmHg, check if there is any leaking point and repair the them. If after over 2 hours vacuumizing, the vacuum degree is below -755mmHg, close the VL and VH on the meter separator and stop vacuumizing. 1 hour later to confirm if the vacuum degree changes. If changes, it indicates there is leaking point in the system. Check the leaking point and repair. After finishing the above vacuumizing, change the vacuum pump into refrigerant pump to charge the refrigerant. 7. Charging amount of refrigerant When the total length (L) of the two indoor units' connecting pipe is less than 5m, it is unnecessary to charge additional refrigerant. If the connecting pipe (L) exceeds 5m, it shall charge Mg additional refrigerant per meter. That is: Refrigerant charging amount = (L-5) x M (g) For AU142AFBEA, AU182AFBEA, M=30 For AU242AHBEA, AU282AHBEA, AU28NAHBEA, AU36NAIBEA, AU42NAIBEA, AU52NAIBEA M=65 Only in COOLING operation can charge the additional refrigerant. When charging, the refrigerant shall be charged from the charging nozzle of low pressure vavle. Be carefull when charging refrigerant, do not let the air mix into the system,and must charge the additional refrigerant in liquid condition. 10