Pipe Connection - Mitsubishi Electric MXZ-A26/32WV Installation Manual

4. Flaring work
• Perform flaring work using flaring tool as shown in the right.
A (mm)
Outside diameter Flare tool for R410A Conventional flare tool
clutch type Clutch type
ø6.35 mm 0 to 0.5 1.0 to 1.5
ø9.52 mm 0 to 0.5 1.0 to 1.5
ø12.7 mm 0 to 0.5 1.0 to 1.5
ø15.88 mm 0 to 0.5 1.0 to 1.5
Firmly hold copper pipe in a die in the dimension shown in the
table above.
5. Check
• Compare the flared work with the figure below.
• If flare is noted to be defective, cut off the flared section
and perform flaring work again.
5-3

PIPE CONNECTION

Note:
Fasten a flare nut with a torque wrench as specified in the table below.
When fastened too tight, a flare nut may broken after a long period and cause a leakage of refrigerant.
1. Indoor unit connection
• Connect both liquid pipe and gas pipe to indoor unit.
- Apply a thin coat of refrigeration oil to the seat surface of pipe.
- For connection, align the center of both pipe and union, then tighten the first 3 to 4 turns in flare nut by
hand.
- For tightening the union part of the indoor unit side, use the table below as a standard and tighten
the flare nut with two wrenches. Excessive tightening damages the flared section.
Tightening torque
Pipe diamete
N·m
ø6.35 mm 13.7 to 17.7
ø9.52 mm 34.3 to 41.2
ø12.7 mm 49.0 to 56.4
ø15.88 mm 73.5 to 78.4
2. Outdoor unit connection
• Connect pipes to the pipe joint part of the stop valve in the same method as the indoor unit.
- For tightening, use the same tightening torque applied for indoor unit and tighten the flare nut with
torque wrench or spanner.
INSULATION AND TAPING
1 Cover piping joints with pipe cover.
2 For outdoor unit side, surely insulate every piping including valves.
3 Using piping tape E, apply taping starting from the entry of outdoor unit.
• Fix the end of piping tape E with adhesive tape.
• When piping has to be arranged through above ceiling, closet or area where the temperature and humidity
are high, wind additional commercially sold insulation for prevention of condensation.
Flaring tool
Wing nut type
Clutch type
1.5 to 2.0
A
1.5 to 2.0
2.0 to 2.5
—
Die
Copper pipe
Flare nut
Smooth all around Inside is shining without any scratches
Even length
all around
kgf·cm
140 to 180
350 to 420
500 to 575
750 to 800
5-4 PURGING PROCEDURES • LEAK TEST
• Perform the manifold valve work securely according to the installation manual of the manifold valve.
Wing nut type
Connect the refrigerant pipes (both liquid pipe and gas pipe) between the indoor and
the outdoor unit.
York
Remove the service port cap of the stop valve on the gas pipe side of the outdoor unit.
Die
(The stop valve will not work in it initial state fresh out of the factory [totally closed with
cap on].)
Copper pipe
Connect the gauge manifold valve and the vacuum pump to the service port of the stop
valve on the gas pipe side of the outdoor unit.
Run the vacuum pump. (Vacuumize for more than 15 minutes.)
Check the vacuum with the gauge manifold valve, then close the gauge manifold valve
and stop the vacuum pump.
Leave it as is for one or two minutes. Make sure the pointer of the gauge manifold
valve remains in the same position. Confirm that the pressure gauge shows –0.101
MPa [Gauge] (–760 mmHg).
Charge hose (for R410A)
Remove the gauge manifold valve quickly from the service port of the stop valve.
After refrigerant pipes are connected and evacuated, fully open all stop valves on both
sides of gas pipe and liquid pipe.
Operating without fully opening lowers the performance and this causes trouble.
Pipe length up to 40 m
No gas charge is needed.
Tighten the cap to the service port to obtain the initial status.
7
PURGING PROCEDURES
Compound pressure
-0.101MPa
gauge (for R410A)
(-760 mmHg)
Pressure gauge
(for R410A)
Stop valve Gauge manifold
(gas side) valve (for R410A)
Handle
Handle High
Low
Charge hose
Service port
(for R410A)
Vacuum
pump (or the vacuum
Window pump with the
function to prevent
Adapter for
the back flow)
preventing
the back flow
Pipe length exceeding 40 m
Charge the prescribed
amount of gas. (refer to 5-1)
Retighten the cap.
Leak test