Mitsubishi Electric MXZ-2C20NA2 Installation Manual page 6

3. FLARING WORK AND PIPE CONNECTION
3-1. FLARING WORK
1) Cut the copper pipe correctly with pipe cutter. (Fig. 1, 2)
2) Completely remo e all burrs from the cut cross section of
pipe. (Fig. 3)
Aim the copper pipe downward while remo ing burrs to
pre ent burrs from dropping in the pipe.
3) Remo e are nuts attached to indoor and outdoor units,
then put them on pipe ha ing completed burr remo al.
(Not possible to put them on after aring wor .)
4) Flaring wor (Fig. 4, 5). Firmly hold copper pipe in the
dimension shown in the table. Select A inch (mm) from
the table according to the tool selected.
5) Chec
Compare the ared wor with Fig. 6.
If are is noted to be defecti e, cut off the ared section
and do aring wor again.
Pipe diameter B
[inch (mm)] [inch (mm)]
1/4 (ø6.35) 21/32 (17)
3/8 (ø9.52) 7/8 (22)
1/2 (ø12.7) 1-1/32 (26)
5/8 (ø15.88) 1-5/32 (29)
3-2. PIPE CONNECTION
1) Apply a thin coat of refrigeration oil ( ) to the ared ends of the pipes and the
pipe connections of the outdoor unit.
2) Align the center of the pipe with that of the pipe connections of the outdoor unit,
then hand tighten the are nut 3 to 4 turns.
3) Tighten the are nut with a torque wrench as speci ed in the table.
O er-tightening may cause damage to the are nut, resulting in refrigerant
lea age.
e 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) Co er piping joints with pipe co er.
2) For outdoor unit side, surely insulate e ery piping including al es.
3) Using piping tape (E), apply taping starting from the entry of outdoor unit.
Stop the end of piping tape (E) with tape (with adhesi e agent attached).
When piping ha e to be arranged through abo e ceiling, closet or where the
temperature and humidity are high, wind additional commercially sold insulation
to pre ent condensation.
. PURGING PROCEDURES, LEAK TEST, AND TEST RUN
-1. PURGING PROCEDURES AND LEAK TEST
1) Remo e ser ice port cap of stop al e on the side of the outdoor unit gas pipe.
(The stop al es are fully closed and co ered in caps in their initial state.)
2) Connect gauge manifold al e and acuum pump to ser ice port of stop al e
on the side of the outdoor unit gas pipe.
3) Run the acuum pump. ( acuumize for more than 15 minutes.)
4) Chec the acuum with gauge manifold al e, then close gauge manifold
al e, and stop the acuum pump.
5) Lea e as it is for one or two minutes. Ma e sure the pointer of gauge manifold
al e remains in the same position. Con rm that pressure gauge shows -14.7
psi [ auge] (-0.101 MPa).
6) Remo e gauge manifold al e quic ly from ser ice port of stop al e.
7) Fully open all stop al es 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 ser ice port to obtain the initial status.
10) Lea test
En-5
Clutch type
A [inch (mm)]
Clutch type tool for R410A Clutch type tool for R22
0 to 0.02 0.04 to 0.06
(0 to 0.5) (1.0 to 1.5)
ood
Copper
pipe
Tilted Une en urred
Fig. 1
Flaring tool
Die
Flare nut
Wing nut type
Fig. 4
Wing nut type tool for R22
0.06 to 0.08
(1.5 to 2.0)
0.08 to 1.0
(2.0 to 2.5)
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.
*4 to 5 turns
*Close
*Open
exagonal wrench
Ser ice port cap
(Torque 13.7 to
17.7 N m, 140 to
180 gf cm)
Precautions when us-
ing the control al e
Body
Close
A
Open
Control
Ser ice port
al e
No good
Copper pipe
urr
Spare reamer
Fig. 2
Smooth all
around
Copper pipe
B
Fig. 5
Tightening torque
ft-Ib N m
10 to 13 13.7 to 17.7
25 to 30 34.3 to 41.2
36 to 42 49.0 to 56.4
54 to 58 73.5 to 78.4
Compound pressure
–0.101MPa
Stop al e cap
gauge (for R410A)
(–760 mm g)
(Torque 19.6 to
29.4 N m, 200
to 300 gf cm)
andle
Low
Stop al e
acuum pump
Stop al e
for LI UID
(for R410A)
for AS
When attaching the control al e
to the ser ice port, al e core may
deform or loosen if excess pres-
sure is applied. This may cause
gas lea .
When attaching the control al e to
the ser ice port, ma e sure that the
al e core is in closed position, and
Charge hose
then tighten part A. Do not tighten
(for R410A)
part A or turn the body when al e
core is in open position.
Pipe cutter
Fig. 3
Inside is shin-
ing without any
scratches.
E en length
all around
Fig. 6
gf cm
140 to 180
350 to 420
500 to 575
750 to 800
Pressure gauge
(for R410A)
auge manifold
al e (for R410A)
andle igh
Charge hose
(for R410A)