-
17
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'17 • SCM-T-225
4. CONNECTING PIPING WORK
1. Restrictions on unit installation
Abide by the following restrictions on unit installation.
Improper installation can cause compressor failure or performance degradation.
Piping length
One indoor unit MAX 25m
All indoor unit
MAX 70m
Hight difference
MAX
25m
MAX 20m
MAX 20m
Outdoor
unit
Indoor
unit
Indoor
unit
Indoor
unit
Indoor
unit
Length of chargeless
refrigerant pipe
40m
2. Preparation of connecting pipe
2.1. Selecting connecting pipe
Select connecting pipe according to the following table.
Indoor unit
Model 20/25/35
Model 50/60
Gas pipe
ø9.52
ø12.7
Liquid pipe
ø6.35
ø6.35
• Pipe wall thickness must be greater than or equal to 0.8 mm.
• Pipe material must be O-type (Phosphorus deoxidized seamless copper pipe ICS 23.040.15, ICS
77.150.30).
2.2. Cutting connecting pipe
(1) Cut the connecting pipe to the required length with pipe cutter.
(2) Hold the pipe downward and remove the burrs. Make sure that no foreign material enters the pipe.
(3) Cover the connecting pipe ends with the tape.
3. Piping work
Check that both liquid and gas service valves are fully closed.
Carry out the piping work with service valves fully closed.
Liquid service valve
Gas service valve
3.1. Flaring pipe
(1) Take out
nuts from the
service valves of outdoor unit.
If a 5.0, 6.0 kw class indoor unit (gas side pipe 12.7) is going to be connected to the
service valves
(9.52), variable joints available as accessories must be applied to the gas side service valves. Se-
curely the copper packing between the
service valve and the variable diameter joint to
shifting.
Engage
nuts onto connecting pipes.
Service
valve
Liquid side service valve ( 6.35)
6.35 pipe
50,60 model
Indoor unit
Gas side service
valve ( 9.52)
Copper packing
Variable diameter joint
( 9.52 - 12.7)
12.7 pipe
(2) Flare the pipes according to table and
shown below.
Flare dimensions for R410A are different from those for conventional refrigerant.
Although it is recommended to use the
tools designed
for R410A, conventional
tools can also be used by adjusting the measurement of protrusion B with a
adjustment gauge.
A
Copper pipe
outer diameter A
0
–0.4
B
Copper pipe
outer diameter
Rigid (clutch) type
R410A
Conventional
ø6.35
9.1
ø6.35
0-0.5
1.0-1.5
ø9.52
13.2
ø9.52
ø12.7
16.6
ø12.7
3.2. Connecting pipes
(1) Connect pipes on both liquid and gas sides.
Service valve
for room D
Service valve
for room C
Service valve
for room B
Service valve
for room A
(2) Tighten nuts to
torque shown in the table below.
Service valve size (mm)
Tightening torque (N·m)
ø6.35 (1/4")
14-18
ø9.52 (3/8")
34-42
ø12.7 (1/2")
49-61
Do not hold the valve cap area with a spanner
CAUTION
• Do not apply refrigerating machine oil to the
surface. It can cause refrigerant leakage.
• Do not apply excess torque to the
nuts. The
nuts may crack resulting in refrigerant leakage.
4. Evacuation
(1) Connect vacuum pump to gauge manifold. Connect charge hose of gauge manifold to a service port
of outdoor unit.
(2) Run the vacuum pump for at least one hour after the vacuum gauge shows -0.1MPa (–76cm Hg).
(3)
that the vacuum gauge indicator does not rise even if the system is left for 15 minutes or more.
Vacuum gauge indicator will rise if the system has moisture left inside or has a leakage point.
Check the system for the leakage point. If leakage point is found, repair it and return to (1) again.
(4) Close the Handle Lo and stop the vacuum pump.
Keep this state for a few minutes to make sure that the compound pressure gauge pointer does not
swing back.
(5) Remove valve caps from liquid service valve and gas operation valve.
(6) Turn the liquid service valve's rod 90 degree counterclockwise with a hexagonal wrench key to
open valve.
Close it after 5 seconds, and check for gas leakage.
Using soapy water, check for gas leakage from indoor unit's
and outdoor unit's
and valve rods.
Wipe off all the water after completing the check.
(7) Disconnect charging hose from gas service valve's service port and fully open liquid and gas service
valves. (Do not attempt to turn valve rod beyond its stop.)
(8) Tighten service valve caps and service port cap to the
torque shown in the table below.
Service valve size (mm)
Service valve cap tightening
torque (N·m)
Service port cap tightening
torque (N·m)
ø6.35 (1/4")
20-30
10-12
ø9.52 (3/8")
ø12.7 (1/2")
25-35
(9) Repeat the above steps (1) to (8) for all connected indoor units.
Charge hose
Handle Lo
Valve cap
Liquid service valve
Gas service valve
Service port
Compound pressure gauge
Pressure gauge
Gauge manifold
Handle Hi
Vacuum pump
CAUTION
• To prevent the entering of different oil into the refrigeration system, do not use tools designed for any
other refrigerant type (R22, R407C, etc.).
• To prevent vacuum pump oil from entering into the refrigerant system, use a
prevention adapter.
5. Additional refrigerant charge
Additional refrigerant charge is required only when connecting pipe length exceeds 40 m.
5.1 Calculating additional refrigerant charge
Additional refrigerant charge can be calculated using the formula given below.
Additional refrigerant charge (g) = { Connecting pipe length (m) – Factory charged length 40 (m) } x 20 (g/m)
NOTE
• If additional refrigerant charge calculation result is negative, there is no need to remove the refrigerant.
• If refrigerant recharge is required for the unit with connecting pipe length 40m or shorter, charge the
factory charged amount as shown in the table below.
Model SCM71/80
Factory charged amount(kg)
3.15
5.2 Charging refrigerant
(1) Charge the R410A refrigerant in liquid phase from service port with both liquid and gas service
valves shut. Since R410A refrigerant must be charged in the liquid phase, make sure that refriger-
ant is discharged from the cylinder in the liquid phase all the time.
(2) When it is
to charge a required refrigerant amount, fully open both liquid and gas service
valves and charge refrigerant, while running the unit in the cooling mode. When refrigerant is
charged with the unit being run, complete the charge operation within 30 minutes.
(3) Write the additional refrigerant charge calculated from the connecting pipe length on the label
attached on the service cover.
CAUTION
Running the unit with an
quantity of refrigerant for a long time can cause unit malfunction.
5. ELECTRICAL WIRING WORK
WARNING
• Make sure that all the electrical work is carried out in accordance with the national or regional
electrical standards.
• Make sure that the earth leakage breaker and circuit breaker of appropriate capacities are installed
(Refer to the table given below).
• Do not turn on the power until the electrical work is completed.
• Do not use a condensive capacitor for power factor improvement under any circumstances.
(It does not improve power factor. Moreover, it can cause an abnormal overheat accident).
Breaker
Model
Phase
Earth leakage breaker
Circuit breaker
SCM71/80
Single phase
Leakage current: 30mA,
0.1sec or less
Over current: 25A
Main fuse
Model
Parts No.
SCM71/80
250V 20A
SSA564A136A
1.Preparing cable
(1) Selecting cable
Select the power source cable and connecting cable in accordance with the
mentioned below.
(a) Power source cable
3-core* 2.5mm
2
or more, conformed with 60245 IEC57
When selecting the power source cable length, make sure that voltage drop is less than 2%.
If the wire length gets longer, increase the wire diameter.
(b) Connecting cable
4-core* 1.5mm
2
, conformed with 60245 IEC57
* 1 Earth wire is included (Yellow/Green).
(2) Arrange each wire length as shown below.
Make sure that each wire is stripped 10mm from the end.
<Power source cable>
<Connecting cable>
<Wire end>
Earth wire
40mm or more
30mm or more
40mm or more
Earth wire
30mm or more
10mm
(3) Attach round crimp-type terminal to each wire as shown in the below.
Select the size of round crimp-type terminal
after considering the
of terminal block and wire
diameter.
10mm
Round crimp-type terminal
Sleeve
CAUTION
Power source cable and connecting cable must conform to the
mentioned in the manual.
Using cables with wrong
may result in unit malfunction.
2.Connecting cable
(1) Remove the service cover and the terminal cover.
(2) Connect the cables according to the instructions and
given below.
(a) Connect the earth wire of power source cable.
An earth wire must be connected before connecting the other wires of power source cable.
Keep the earth wire longer than the remaining two wires of power source cable.
(b) Connect the remaining two wires (N and L) of power source cable.
(c) Connect the wires of connecting cables. Make sure that for each wire, outdoor and indoor side
terminal numbers match. Terminal number A of the outdoor unit is used for A indoor unit and
terminal number B for B indoor unit respectively.
Earth wire shall be Yellow/Green (Y/G) in color and longer than other wires for safety reason.
(3) Fasten the cables properly with cable clamps so that no external force may work on terminal
connections.
Moreover, make sure that cables do not touch the piping, etc. When cables are connected, make
sure that all electrical components within the electrical component box are free of loose connector
coupling or terminal connection.
<Circuit diagram>
L
N
Circuit
Power
source
breaker
Earth
leakage
breaker
Outdoor unit
1 2 3
1 2 3
1 2 3
1 2 3
1 2 3
1 2 3
1 2 3
unit A
unit B
unit C
unit A
unit B
Indoor unit
unit C
1 2 3
unit D
unit D
Connecting
cable
6. FINISHING WORK
NOTE
● Make sure to match the piping and
wiring from each unit to the outdoor
unit.
● Be careful because if connections
are wrong, normal operation cannot
be achieved and may damage the
compressor.
1. Heating and condensation prevention
(1) Dress the connecting pipes (both liquid and gas pipes) with insulation to prevent it from heating
and dew condensation.
Use the heat insulating material which can withstand 120°C or higher temperature. Make sure that
insulation is wrapped tightly around the pipes and no gap is left between them.
(2) Wrap the refrigerant pipings of indoor unit with indoor unit heat insulation using tape.
(3) Cover the
joints (indoor side) with the indoor unit heat insulation and wrap it with
an insulation pad (standard accessory provided with indoor unit).
(4) Wrap the connecting pipes, connecting cable and drain hose with the tape.
(2)
(3)
(4)
Tape
Insulation pad
Position it so that the slit area faces upward.
Connecting cable
Liquid pipe
Drain hose
Gas pipe
Insulation
Tape
NOTE
Locations where relative humidity exceeds 70%, both liquid and gas pipes need to be dressed with 20mm
or thicker heat insulation materials.
CAUTION
• Improper insulation can cause condensate(water) formation during cooling operation.
Condensate can leak or drip causing damage to household property.
• Poor heat insulating capacity can cause pipe outer surface to reach high temperature during heating
operation. It can cause cable deterioration and personal injury.
2.Finishing work
(1) Make sure that the exterior portion of
connecting pipes, connecting cable and
drain hose is wrapped properly with
tape. Shape the connecting pipes to
match with the contours of the pipe as-
sembly route.
(2) Fix the pipe assembly with the wall us-
ing clamps and screws. Pipe assembly
should be anchored every 1.5m or less
to isolate the vibration.
(3) Install the terminal cover and the service
cover securely. Water may enter the unit
if service cover is not installed properly,
resulting in unit malfunction and failure.
CAUTION
Make sure that the connecting pipes do not touch the components within the unit. If pipes touch the
internal components, it may generate abnormal sounds and/or vibrations.
7. PUMP DOWN
(1) Connect charge hose of gauge manifold to a service port of outdoor unit.
(2) Close the liquid service valves for all connected indoor units with hexagonal wrench key.
(3) Fully open the gas service valves with hexagonal wrench key.
(4) Carry out forced cooling operation for all connected indoor units (For forced cooling operation procedure,
refer to indoor unit installation manual).
(5) When the low pressure gauge becomes 0.01MPa, close the gas service valves and stop forced cooling
operation.
Gauge manifold
Charge hose
Service port
8. INSTALLATION TEST CHECK POINTS
After
the installation work, check the following points again before turning on the power.
Conduct test run (Refer to indoor unit installation manual) and ensure that the unit operates properly.
RPC012A920C
Power source voltage complies with the rated voltage of air-conditioner.
Earth leakage breaker and circuit breaker are installed.
Power cable and connecting cable are securely
to the terminal block.
Both liquid and gas service valves are fully open.
No gas leaks from the joints of the service valves.
Indoor and outdoor side pipe joints have been insulated.
Drain hose (if installed) is
properly.
Screw of the service cover is tightened properly.
View of Terminal block
unit A unit B
unit C unit D
POWER
source
Indoor unit
Indoor unit
unit D
unit C
unit B
unit A
Outdoor
unit
unit D
unit C
unit B
unit A
Outdoor
unit
D
C
A
B
D
C
A
B
Piping
Wiring
Cable
clamp
Cable
clamp
Power
source
cable
Connecting
cable
Pipe
assembly
Clamp
Screw
prevent
RPC012A920C.pdf 17.11.3 6:03:19 PM
