Air Purging; Earthing Work - Mitsubishi Heavy Industries SRK20MA-S Technical Manual

Flaring
Measurement B
Flaring Copper
block pipe
Do not apply excess torque to the flared nuts. Otherwise, the flared nuts may crack depending on the conditions and
refrigerant leak may occur.
Connection
Indoor
Liquid side
Gas side
(Do not turn)
○ Connect the pipes on both liquid and gas sides.
○ Tighten the nuts to the following torque.
Liquid side
Gas side

Air purging

① Secure all flare nuts on both indoor and outdoor sides
to prevent leaks from the pipes.
② Connect the operation valves, charge hose, manifold
valve and vacuum pump as shown in the right figure.
③ Fully open Handle Lo for the manifold valve, and
pump a vacuum for over 15 minutes. Ensure that the
meter is indicating -76cmHg (-0.1MPa).
④ After vacuuming, fully open the operation valve (both
liquid and gas sides) with a hexagon wrench.
⑤ Ensure that there are no gas leaks from the joints in
the indoor and outdoor units.
● Since the system uses service ports differing in diameter from those found on the conventional models, a
charge hose (for R22) presently in use is not applicable. Please use one designed specifically for R410A.
● Please use an anti-reverse flow type vacuum pump adapter so as to prevent vacuum pump oil from
running back into the system. Oil running back into an air-conditioning system may cause the refrigerant
cycle to break down.
Heat insulation for joints
Cover the joint with insulation material for the
indoor unit and tape it.
Vinyl tape

Earthing Work

○ Earth work shall be carried out without fail in order to prevent electric shock
and noise generation.
○ The connection of the earth cable to the following substances causes
dangerous failures, therefore it shall never be done. (City water pipe, Town
gas pipe, TV antenna, lightning conductor, telephone line, etc.)
Copper pipe
Model
diameter
Use a flare tool designed for R410A or a conventional flare tool. Please note that measurement B (protrusion from the
flaring block) will vary depending on the type of flare tool in use. If a conventional flare tool is used, please use a copper
pipe gauge or a similar instrument to check protrusion so that you can keep measurement B to a correct value.
Caution
Position so the slit
comes on top.
Measurement B
Conventional (R22) flare tool
Clutch type flare tool
Clutch type
for R410A
Outdoor
Liquid side
Gas side
○ Connect the pipes on both liquid and gas sides.
○ All torques are the same as on the indoor liquid
side.
Compound
pressure gauge
Operation valve
(2-way valve)
Operation valve
(3-way valve)
Handle Lo
Service port
Charge hose
(Designed specifically for
R410A)
Finish and fixing
Apply exterior tape and
Pipes
shape along the place where
Crossover wires
the pipes will be routed.
Ground wire
Secure to the wall with a
Exterior tape
pipe clamp.
Drainage pipe
Tapping screw
Pipe clamp
- 36 -
Wing nut type
Pressure gauge
Gauge manifold
(Designed specifically for R410A)
Handle Hi
Charge hose (Designed specifically for R410A)
Vacuum pump adapter (Anti-reverse flow type)
(Designed specifically for R410A)