Mitsubishi Electric MXZ-3B24NA Manual De Instalación página 6

3=1. FLARING WORK
1) Cut the copper pipe correctly with pipe cutter. (Fig. t, 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 sec-
tion and do flaring work again.
Fig. t
Flaring tool
Clutch type Wing nut type
Fig. 4
Good No good
Tilted Uneven Burred
Fig. 2
A
Die -J_- Copper pipe
/
Flare nut
Fig. 5
urr C_:C_s; aPleP e.....
I_ _,,_.Pipe cutter I_ _
Fig. 3
Inside is shin-
Smooth al! ing without any
..... d z,_¢ \ .... tches.
_-.i_ Even length
all around
i
Fig. 6
II
Pipe diameter Nut
[mm (inch)] (mm)
e6.35 (t/4) t7
e9.52 (3/8) 22
et2.7 (t/2) 26
et5.88 (5/8) 29
j Clutch type tool for R410A
0 to 0.5
(0 to 0.02)
A [mm (inch)]
Clutch type tool for R22
1.0 to t .5
(0.04 to 0.06)
Wing nut type tool for R22 N.m
1.5 to 2.0 t3.7 to 17.7
(0.06 to 0.08) 34.3 to 41.2
2.0 to 2.5 49.0 to 56.4
(0.08 to 1.0) 73.5 to 78.4
Tightening torque
kgf-cm
140 to t80
350 to 420
500 to 575
750 to 800
ftolb
t0 to t3
25 to 30
36 to 42
54 to 58
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.
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=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 t5 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) (-30 in. Hg).
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 t-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
0.101MPa
[-760 mmHg Compound pressure
*4 to 5 turns Stop valve cap (-30 in. Hg)] gauge (for R410A)
(Torque 19.6 to 29.4 Nora, Pressure gauge
*Close 200 to 300 kgfocm,15 to R410A)
*Ope 22 ft.lb)
e manifold
"_- Stop valve valve(for R410A)
_L_ for GAS Handle High
Hexagonal wrench Low
e hose
(for R410A)
Service port
(Torque 13.7 to
17.7 N,m, 140 to
180 kgfocm, 10 to
13 ffolb)
,-Stop valve
for LIQUID
Vacuum pump
(for R410A)
Precautions when using When attachinq the control valve to
the contro va ve the service port valve core may de-
form or loosen if excess pressure is
---',,]V_'_ U applied. This may cause qas leak.
CentreA
valve ---"_ II::_:_q_&_:d
Ope.--_ i ._Service port When attaching the control valve to
CIose_"€_ _'_-Ld_'=_m- '_- _'_/ the service port, make sure that the
valve core is in closed position, and
...... then tighten part A. Do not tighten
t Charge hose part A or turn the body when valve
Body (for R410A) core is in open position.
En-5