Refrigerant Piping Work - Mitsubishi Electric SLZ-A09AR Installation Manual

5. Refrigerant piping work

b
a
90°
Fig. 5-3
b
a
c
d
Fig. 5-4
Fig. 5-5
a
A
d
b
c
Fig. 5-6
a b
B
d
c
Fig. 5-7
A
Fig. 5-8
G
F
B,C
J
I
H
Fig. 5-9
6
c a Copper tubes
b Good
d e f
c No good
d Tilted
e Uneven
f Burred
a Burr
b Copper tube/pipe
c Spare reamer
d Pipe cutter
a
a Flare nut
b Copper tube
b
a Flaring tool
e
b Die
c Copper tube
b
d Flare nut
c
e Yoke
e f g h
i
As viewed from A
A Refrigerant pipe and insulating material
(Procure locally)
B Pipe cover (large) (Accessory)
C Pipe cover (small) (Accessory)
D Refrigerant pipe (gas)
E Refrigerant pipe (liquid)
F Band (Accessory)
G Cross-sectional view of connection
H Refrigerant pipe
I Insulating material
J Squeeze
5.2. Flaring work
• Main cause of gas leakage is defect in flaring work.
Carry out correct flaring work in the following procedure.
5.2.1. Pipe cutting (Fig. 5-3)
• Using a pipe cutter cut the copper tube correctly.
5.2.2. Burrs removal (Fig. 5-4)
• Completely remove all burrs from the cut cross section of pipe/tube.
• Put the end of the copper tube/pipe to downward direction as you remove burrs in
order to avoid burrs drop in the tubing.
5.2.3. Putting nut on (Fig. 5-5)
• Remove flare nuts attached to indoor and outdoor unit, then put them on pipe/tube
having completed burr removal.
(not possible to put them on after flaring work)
5.2.4. Flaring work (Fig. 5-6)
• Carry out flaring work using flaring tool as shown at the right.
Pipe diameter A (mm)
(mm) When the tool for R410A is used
Clutch type
6.35 0 - 0.5
9.52 0 - 0.5
12.7 0 - 0.5
Firmly hold copper tube in a die in the dimension shown in the table at above.
5.2.5. Check (Fig. 5-7)
• Compare the flared work with a figure in rightside hand.
• If flare is noted to be defective, cut off the flared section and do flaring work again.
a Smooth all around
b Inside is shining without any scratches
c Even length all around
d Too much
e Tilted
5.3. Refrigerant and drainage piping locations (Fig.5-8)
A Drain pipe
B Ceiling
C Grille
D Refrigerant pipe (liquid)
E Refrigerant pipe (gas)
F Water supply inlet
G Main unit
5.4. Pipe connection (Fig. 5-9)
Indoor unit
1) When using commercially available copper pipes:
• Apply thin layer of refrigerant oil to pipe and joint seating surface before tightening
flare nut.
• Use two wrenches to tighten piping connections.
• Air-purge the refrigerant piping using your own refrigerant gas (don't air-purge the
refrigerant charged in the outdoor unit).
• Use leak detector or soapy water to check for gas leaks after connections are com-
pleted.
• Use refrigerant piping insulation provided to insulate indoor unit connections. Insu-
late carefully following shown below.
2) Heat insulation for refrigerant pipes:
1 Wrap the enclosed large-sized pipe cover around the gas pipe, making sure that
the end of the pipe cover touches the side of the unit.
2 Wrap the enclosed small-sized pipe cover around the liquid pipe, making sure
that the end of the pipe cover touches the side of the unit.
3 Secure both ends of each pipe cover with the enclosed bands. (Attach the bands
20 mm from the ends of the pipe cover.)
See that stop valve on outdoor unit is fully shut (unit is shipped with valve shut). After
all piping connections between indoor and outdoor unit have been completed,
vaccuum-purge air from system through the service port for the stop valve on the
outdoor unit.
After completing procedures above, open outdoor unit stop valves stem fully. This
completes connection of refrigerant circuit between indoor and outdoor units. Stop
valve instructions are marked on outdoor unit.
Dimension
+0
B (mm)
-0.4
9.1
13.2
16.6
f Scratch on flared plane
g Cracked
h Uneven
i Bad examples