Part Names And Functions - Mitsubishi Electric MU-A09WA Service Manual

3.Refrigerant oil
Apply the special refrigeration oil (accessories: packed with indoor unit) to the flare and the union seat surfaces.
4.Air purge
• Do not discharge the refrigerant into the atmosphere.
Take care not to discharge refrigerant into the atmosphere during installation, reinstallation, or repairs to the refrigerant
circuit.
• Use the vacuum pump for air purging for the purpose of environmental protection.
5.Additional charge
For additional charging, charge the refrigerant from liquid phase of the gas cylinder.
If the refrigerant is charged from the gas phase, composition change may occur in the refrigerant inside the cylinder and the
outdoor unit. In this case, ability of the refrigeration cycle decreases or normal operation can be impossible. However,
charging the liquid refrigerant all at once may cause the compressor to be locked. Thus, charge the refrigerant slowly.
Refrigerant gas
cylinder
operating valve
2

PART NAMES AND FUNCTIONS

MU-A09WA
Union
Indoor unit
Charge hose (for R410A)
Refrigerant gas cylinder
for R410A with siphon
Refrigerant (liquid)
Electronic scale for refrigerant charging
Air inlet
(back and side)
Piping
Drain hose
Air outlet
Drain outlet
Stop valve
Liquid pipe
Gas pipe
Service port
Gauge manifold
valve (for R410A)
MU-A12WA
5
Outdoor unit
Air inlet
(back and side)
Piping
Drain hose
Air outlet
Drain outlet