Flare Connection - Mitsubishi Electric MSZ-GS18NA Installation Manual

3. Outdoor Unit Installation 3. Outdoor Unit Installation
3-1. Connecting Wires for the Outdoor Unit 3-1. Connecting Wires for the Outdoor Unit
1) Remove the service panel. 1) Remove the service panel.
2) Remove the conduit cover. 2) Remove the conduit cover.
3) Attach the conduit connectors to the conduit plate with lock nuts then secure it against unit 3) Attach the conduit connectors to the conduit plate with lock nuts then secure it against unit
with screws. with screws.
4) Connect the ground wires of indoor/outdoor unit connecting wire (A) and power supply cord (K) 4) Connect the ground wires of indoor/outdoor unit connecting wire (A) and power supply cord (K)
to the TB support. to the TB support.
5) Loosen the terminal screws, then attach indoor/outdoor unit connecting wire (A) and power 5) Loosen the terminal screws, then attach indoor/outdoor unit connecting wire (A) and power
supply cord (K) from the indoor unit correctly to the terminal block. Attach the wires to the supply cord (K) from the indoor unit correctly to the terminal block. Attach the wires to the
terminal block securely so that the cores cannot be seen, and no external force affects the terminal block securely so that the cores cannot be seen, and no external force affects the
connecting section of the terminal block. connecting section of the terminal block.
6) Firmly tighten the terminal screws. After tightening, verify that the wires are tightly fastened. 6) Firmly tighten the terminal screws. After tightening, verify that the wires are tightly fastened.
7) Install the conduit cover. 7) Install the conduit cover.
8) Install the service panel securely. 8) Install the service panel securely.
Service panel Service panel
Lock nut Lock nut
Conduit cover Conduit Conduit cover Conduit
plate plate

3-2. Flare Connection

3-2. Flare Connection
1) Cut the copper pipe as straight as possible with a pipe cutter. (Fig. 1, 2) 1) Cut the copper pipe as straight as possible with a pipe cutter. (Fig. 1, 2)
2) Remove all burrs from the cut section of the pipe, ensuring that precautions are taken to 2) Remove all burrs from the cut section of the pipe, ensuring that precautions are taken to
avoid getting metal shavings into the piping. (Fig. 3) avoid getting metal shavings into the piping. (Fig. 3)
3) Remove flare nuts attached to indoor and outdoor units, then put them on pipe. 3) Remove flare nuts attached to indoor and outdoor units, then put them on pipe.
4) Flaring work (Fig. 4, 5). Firmly hold copper pipe in the dimension shown in the table. Select A 4) Flaring work (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 you use. inch (mm) from the table according to the tool you use.
5) Check 5) Check
• Compare the flared work with Fig. 6. • Compare the flared work with Fig. 6.
• If flare is defective, cut off the section and repeat procedure. • If flare is defective, cut off the section and repeat procedure.
B B
Pipe diameter Pipe diameter
Clutch Clutch
inch inch
inch (mm) inch (mm)
type tool type tool
(mm) (mm)
for R410A for R410A
21/32 21/32
ø 1/4 (6.35) ø 1/4 (6.35)
(17) (17)
7/8 7/8
ø 3/8 (9.52) ø 3/8 (9.52)
(22) (22)
0 to 0.02 0 to 0.02
(0 to 0.5) (0 to 0.5)
1-1/32 1-1/32
ø 1/2 (12.7) ø 1/2 (12.7)
(26) (26)
1-5/32 1-5/32
ø 5/8 (15.88) ø 5/8 (15.88)
(29) (29)
3-3. Pipe Connection 3-3. Pipe Connection
• Fasten flare nut with a torque wrench as specified in the table (refer to 3-2.). • Fasten flare nut with a torque wrench as specified in the table (refer to 3-2.).
• When fastened too tight, flare nut may eventually break and cause refrigerant leakage. • When fastened too tight, flare nut may eventually break and cause refrigerant leakage.
• Be sure to wrap insulation around the piping. Direct contact with the bare piping may • Be sure to wrap insulation around the piping. Direct contact with the bare piping may
result in burns or frostbite. result in burns or frostbite.
Indoor unit connection Indoor unit connection
Connect both liquid and gas pipings to indoor unit. Connect both liquid and gas pipings to indoor unit.
• Do not apply refrigeration oil on screw threads. Excessive tightening torque will result in • Do not apply refrigeration oil on screw threads. Excessive tightening torque will result in
damage on the screw. damage on the screw.
• To connect, first align the center, then tighten the first 3 to 4 turns of flare nut by hand. • To connect, first align the center, then tighten the first 3 to 4 turns of flare nut by hand.
• Use tightening torque table above as a guideline for indoor unit side joints, and tighten • Use tightening torque table above as a guideline for indoor unit side joints, and tighten
using two wrenches. Excessive tightening damages the flare section. using two wrenches. Excessive tightening damages the flare section.
Outdoor unit connection Outdoor unit connection
Connect pipes to stop valve pipe joint of the outdoor unit following the same procedure Connect pipes to stop valve pipe joint of the outdoor unit following the same procedure
detailed in Indoor unit connection. detailed in Indoor unit connection.
• For tightening, use a torque wrench or spanner. • For tightening, use a torque wrench or spanner.
When installing the unit, securely connect the refrigerant pipes before starting the When installing the unit, securely connect the refrigerant pipes before starting the
compressor. compressor.
3-4. Insulation and Taping 3-4. Insulation and Taping
1) Cover piping joints with pipe cover. 1) Cover piping joints with pipe cover.
2) For outdoor unit side, insulate the piping, including valves. 2) For outdoor unit side, insulate the piping, including valves.
3) Apply piping tape (G) starting from the connection on the outdoor unit. 3) Apply piping tape (G) starting from the connection on the outdoor unit.
• When piping has to be installed through a ceiling, closet or where the temperature and • When piping has to be installed through a ceiling, closet or where the temperature and
humidity are high, use additional field-supplied insulation to prevent condensation. humidity are high, use additional field-supplied insulation to prevent condensation.
<MUZ-GS18NA(H)> <MUZ-GS18NA(H)>
<MUY-GS18NA> <MUY-GS18NA>
Terminal block Terminal block
Conduit pipe Conduit pipe
TB support TB support
Indoor/outdoor unit Indoor/outdoor unit
connecting wire (A) connecting wire (A)
A inch (mm) A inch (mm) Tightening torque Tightening torque
Clutch Clutch Wing nut Wing nut
ft-lb ft-lb
type tool type tool type tool type tool
(kgf•cm) (kgf•cm)
for R22 for R22 for R22 for R22
10 to 13 10 to 13
0.06 to 0.06 to
(140 to 180) (140 to 180)
0.08 0.08
(1.5 to (1.5 to
25 to 30 25 to 30
0.04 to 0.04 to
2.0) 2.0)
(350 to 420) (350 to 420)
0.06 0.06
(1.0 to (1.0 to
36 to 42 36 to 42
0.08 to 0.08 to
1.5) 1.5)
(500 to 575) (500 to 575)
0.10 0.10
(2.0 to (2.0 to
54 to 58 54 to 58
2.5) 2.5)
(750 to 800) (750 to 800)
Warning Warning
Lead Lead
wire wire
• Make ground wire a little longer than others. (More than 3-7/8 inches [100 mm]) • Make ground wire a little longer than others. (More than 3-7/8 inches [100 mm])
• For future servicing, leave some slack in the connecting wires. • For future servicing, leave some slack in the connecting wires.
• Be sure to attach each screw to its correspondent terminal when securing the • Be sure to attach each screw to its correspondent terminal when securing the
cord and/or the wire to the terminal block. cord and/or the wire to the terminal block.
Grounding Grounding
terminal terminal
Power supply cord (K) Power supply cord (K)
to conduit cover to conduit cover
N•m N•m
13.7 to 17.7 13.7 to 17.7
34.3 to 41.2 34.3 to 41.2
Clutch type Clutch type
49.0 to 56.4 49.0 to 56.4
73.5 to 78.4 73.5 to 78.4
Even length all around Even length all around
Indoor unit Indoor unit
connection connection
Outdoor unit Outdoor unit
connection connection
19/32 inch 19/32 inch
(15 mm) (15 mm)
<MUZ-GS18NAHZ> <MUZ-GS18NAHZ>
Terminal block Terminal block
TB support TB support
to conduit cover to conduit cover
Good Good
90° 90°
Copper Copper
pipe pipe
Fig. 1 Fig. 1
Copper pipe Copper pipe
Burr Burr
Spare reamer Spare reamer
Pipe cutter Pipe cutter
Flaring tool Flaring tool
Die Die
Flare nut Flare nut
Wing nut type Wing nut type
Fig. 4 Fig. 4
Smooth all around Smooth all around Inside is shining without any scratches. Inside is shining without any scratches.
Flare nut Flare nut
Internal thread side Internal thread side
Tighten the flare nut Tighten the flare nut
with a torque wrench. with a torque wrench.
L1 L2 L1 L2
Power supply cord (K) Power supply cord (K)
Grounding Grounding
terminal terminal
Indoor/outdoor unit Indoor/outdoor unit
connecting wire (A) connecting wire (A)
Power supply cord (K) Power supply cord (K)
No good No good
Tilted Tilted Uneven Burred Uneven Burred
Fig. 2 Fig. 2
Fig. 3 Fig. 3
Copper pipe Copper pipe
Fig. 5 Fig. 5
Fig. 6 Fig. 6
Union joint Union joint
External thread side External thread side
Grip the nut on the Grip the nut on the
union joint with a spanner. union joint with a spanner.