It shall use the vacuum p
ump 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.
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.
Refrigerant piping
10
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 AU182AEEAA, M=30
For AU242AGEAA, AU282AHEAA, AU28NAHEAA, AU362AIEAA,
AU36NAIEAA , AU48NAIEAA, AU60NAIEAA, 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.
6. Piping and indoor unit vacuumizing
7. Charging amount of refrigerant
3-way valve totally closed
(Liquid side)
Indoor units
Indoor
Outdoor
Completely tightened
Completely tightened
Outdoor units
Vacuum pump
Discharging valve
3-way valve totally closed
(Gas side)
Low pressure peizometer
High pressure peizometer
Meter separator
V L VH
Flare part
Flare part
P
Installation Procedure
