Mitsubishi Electric MS-C18TV-E1 WH Service Manual page 4

1.Tools dedicated for the air conditioner with R407C refrigerant
The following tools are required for R407C refrigerant. Some R22 tools can be substituted for R407C tools.
Do not use tools that are used with R22 refrigerant in order to avoid mixing oils.
R407C tools Can R22 tools be used?
Gauge manifold
Charge hose
Gas leak detector
Torque wrench
Flare tool
Vacuum pump
adapter
Electronic scale for
refrigerant charging
2.Refrigerant piping
Do not use copper pipes which are broken, deformed or discoloured.
In addition, be sure that the inner surfaces of the pipes are clean, free of hazardous sulfur and oxides, or have no dust/ dirt,
shaving particles, oil, moisture or any other contamination.
•If there is a large amount of residual oil inside the piping and joints, deterioration of the refrigerant oil will result.
3.Refrigerant oil
Apply the specific refrigeration oil (accessories) to the flare and the union seat surfaces.
4.Air purge
Use the vacuum pump for air purge to protect environments, and to avoid changing the composition of refrigerant.
5.Additional charge
For additional charging, charge the refrigerant with liquid phase slowly using a gas cylinder. If the refrigerant is charged with
gas phase, the composition of refrigerant will change. In this case, ability of the refrigerating cycle decreases or normal
operation can be impossible.
If liquid refrigerant is rapidly charged at once, the compressor may be locked.
NOTE: 1. The R407C is mixed refrigerant which consist of three different kinds of evaporative temperature. As a result, the
R407C occurs the change of composition.
2. Additional refrigerant charge has been changed by change of refrigerant.(R22
R22 : <MU-type> 15g/m
A gauge manifold with a sight glass is recommended for charging the
No
liquid refregerant.
Hose material have been changed to improve the pressure
No
resistance.
No Dedicated for HFC refrigerant.
Yes
Yes
Provided to prevent the back flow of oil. This adapter enables you to use
New
existing vacuum pumps.
New
Use the electronic control scale for measuring the R407C.
R407C : <MU-C18/C24TV> 20g/m
Indoor unit
Refrigerant
gas cylinder
operating
valve
Description
Union
Stop valve
Liquid pipe
Gas pipe
Service port
Gage manifold
Charge hose
Refrigerant gas cylinder
for R407C with siphon
Refrigerant (liquid)
Electronic scale for
refrigerant charging
4
R407C)
Outdoor unit