Air Purging; Earthing Work - Mitsubishi Heavy Industries SRK25QA-S Technical Manual

Flaring
Model
Measurement B
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
Flaring Copper
conventional flare tool is used, please use a copper pipe gauge or a similar instrument to check
block pipe
protrusion so that you can keep measurement B to a correct value.
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.
③Fully 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.)
Measurement B
Copper pipe
Clutch type flare tool
diameter for R410A
Caution
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)
Service port
Charge hose
(Designed specifically for
R410A)
Finish and fixing
Pipes
Crossover wires
Position so the slit
Ground wire
comes on top.
Exterior tape
Drainage pipe
Tapping screw
Pipe clamp
-30-
Conventional (R22) flare tool
Clutch type
Wing nut type
Pressure gauge
Gauge manifold
(Designed specifically for R410A)
Handle Hi
Handle Lo
Charge hose (Designed specifically for R410A)
Vacuum pump adapter (Anti-reverse flow type)
(Designed specifically for R410A)
Apply exterior tape and shape
along the place where the pipes
will be routed.
Secure to the wall with a pipe
clamp.