AUX ALCF-H18/NDR3HA, Service Manual

Page: 149 / 174

R32
High Efficiency DC Inverter LCAC
145
8. Emptying or Vacuum
Before charging the refrigerant to the system, to ensure that there is no impurities, water or
non-condensable gas. So, emptying and vacuum operation should be carried out.
◇
Vacuum: when process this operation please be sure that the connection pipe is
tightened up.
1. Screw off the cover of maintenance valve connection, connect the pressure gauge to
the connection of maintenance valve
2. Connect the vacuum pump to the pressure gauge, turn on the vacuum pump and
pressure gauge to process the vacuum operation toward the indoor unit and piping, while to
ensure that the absolute pressure is no less than 50Pa after this operation.
3. Turn off the pressure gauge and vacuum pump to keep the pressure in the same level
in 20 minutes.
◇
Emptying: when process this operation, please disconnect the high pressure valve with
liquid valve.
1. Connect the gas valve of the stop valve to the thimble side of the rubber hoses, the
other side of rubber hoses should be connected to the refrigerant tank.
2. Open the refrigerant tank valve, using the refrigerant inside the tank with high speed to
empty the air in the indoor unit and the connection piping. When the outlet air becomes mist
(it feels cold by touching it), then the air is emptied.
3. When ensure that the air is emptied, connect and tighten the high pressure valve of
outdoor unit stop valve and liquid side connection pipe, keep this state more than 10
seconds.
4. Use soapy what to test each connection junctions (including lengthen piping welding
junction)
5. Confirmed that there is no leakage, turn off the valve of refrigerant tank, take down the
rubber hose as well.
◇
Turn on the high-low pressure valve of the outdoor unit.
After vacuum and emptying, screw back the cover of the maintenance valve of outdoor unit
low pressure valve, screw off the high-low pressure valve of the outdoor unit (note: shall
totally turned off ). Connect the refrigerant to the system.