Flaring Work And Pipe Connection; Purging Procedures, Leak Test, And Test Run - Mitsubishi Electric MXZ-6D122VA2 Manual De Instalación

3. FLARING WORK AND PIPE CONNECTION

3-1. FLARING WORK
1) Cut the copper pipe correctly with pipe cutter. (Fig. 1, 2)
2) Completely remove all burrs from the cut cross section of pipe. (Fig. 3)
• Aim the copper pipe downward while removing burrs to prevent burrs
from dropping in the pipe.
3) Remove flare nuts attached to indoor and outdoor units, then put them
on pipe having completed burr removal. (Not possible to put them on
after flaring work.)
4) Flaring work (Fig. 4, 5). Firmly hold copper pipe in the dimension shown
in the table. Select A mm from the table according to the tool selected.
5) Check
• Compare the flared work with Fig. 6.
• If flare is noted to be defective, cut off the flared section and do flaring
work again.
A (mm)
Pipe diameter Nut
Clutch Clutch
(mm) (mm)
type tool type tool
for R410A for R22
ø6.35 (1/4") 17
ø9.52 (3/8") 22
0 to 0.5 1.0 to 1.5
ø12.7 (1/2") 26
ø15.88 (5/8") 29
3-2. PIPE CONNECTION
1) Apply a thin coat of refrigeration oil (G) to the flared ends of the pipes
and the pipe connections of the outdoor unit. Do not apply refrigeration
oil on screw threads. Excessive tightening torque will result in damage
on the screw.
2) Align the center of the pipe with that of the pipe connections of the outdoor
unit, then hand tighten the flare nut 3 to 4 turns.
3) Tighten the flare nut with a torque wrench as specified in the table.
• Over-tightening may cause damage to the flare nut, resulting in refriger-
ant leakage.
• Be sure to wrap insulation around the piping. Direct contact with the
bare piping may result in burns or frostbite.
3-3. 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.
• Stop the end of piping tape (E) with tape (with adhesive agent attached).
• When piping have to be arranged through above ceiling, closet or where
the temperature and humidity are high, wind additional commercially
sold insulation to prevent condensation.

4. PURGING PROCEDURES, LEAK TEST, AND TEST RUN

4-1. PURGING PROCEDURES AND LEAK TEST
1) Remove service port cap of stop valve on the side of the outdoor unit
gas pipe. (The stop valves are fully closed and covered in caps in their
initial state.)
2) Connect gauge manifold valve and vacuum pump to service port of stop
valve on the gas pipe side of the outdoor unit.
3) Run the vacuum pump. (Vacuumize for more than 15 minutes.)
4) Check the vacuum with gauge manifold valve, then close gauge manifold
valve, and stop the vacuum pump.
5) Leave as it is for one or two minutes. Make sure the pointer of gauge
manifold valve remains in the same position. Confirm that pressure gauge
shows -0.101 MPa [Gauge] (-760 mmHg).
6) Remove gauge manifold valve quickly from service port of stop valve.
7) Fully open all stop valves on the gas pipe and the liquid pipe. Operating
without fully opening lowers the performance and this causes trouble.
8) Refer to 1-2., and charge the prescribed amount of refrigerant if needed.
Be sure to charge slowly with liquid refrigerant. Otherwise, composition
of the refrigerant in the system may be changed and affect performance
of the air conditioner.
9) Tighten cap of service port to obtain the initial status.
10) Leak test
Tightening torque
Wing nut
type tool N•m kgf•cm
for R22
13.7 to 17.7 140 to 180
1.5 to 2.0
34.3 to 41.2 350 to 420
49.0 to 56.4 500 to 575
2.0 to 2.5
73.5 to 78.4 750 to 800
*4 to 5 turns
*Open
Hexagonal
wrench
Stop valve cap
(Torque 24.4 to
30.4 N•m, 250 to
310 kgf•cm)
Precautions when us-
ing the control valve
Charge hose
(for R410A)
Copper
pipe
Fig. 1
Copper pipe
Burr
Spare reamer
Pipe cutter
Fig. 3
Copper pipe
Die
Flare nut
Fig. 5
WARNING
When installing the unit, securely
connect the refrigerant pipes before
starting the compressor.
CAUTION
When there are the ports which are
not used, make sure their nuts are
tightened securely.
Service port cap Service port cap
*Close
(Torque 10 to 12 N•m, (Torque 10 to 12 N•m,
100 to 120 kgf•cm) 100 to 120 kgf•cm)
Stop valve
for LIQUID
Stop valve
for GAS
When attaching the control valve
to the service port, valve core may
deform or loosen if excess pres-
sure is applied. This may cause
Body Close
Open
gas leak.
Control valve
A
When attaching the control valve to
the service port, make sure that the
valve core is in closed position, and
then tighten part A. Do not tighten
part A or turn the body when valve
core is in open position.
Service port
No good
Good
Tilted Uneven Burred
Fig. 2
Flaring tool
Clutch type Wing nut type
Fig. 4
Inside is shin-
ing without any
Smooth all
scratches.
around
Even length
all around
Fig. 6
Compound pressure
gauge (for R410A)
–0.101MPa
(–760 mmHg)
Pressure gauge
(for R410A)
Gauge mani-
fold valve (for
R410A)
Handle
Handle High
Low
Charge hose
(for R410A)
Stop valve cap
(Torque 21.5 to
27.5 N•m, 220
to 280 kgf•cm)
Vacuum pump
(for R410A)
En-6