Mitsubishi Heavy Industries SCM71ZM-S1 Technical Manual page 18

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
SCM71/80 Single phase
Main fuse
Model
SCM71/80 250V 20A
1.Preparing cable
(1) Selecting cable
Select the power source cable and connecting cable in accordance with the
(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>
30mm or more
40mm or more
Earth wire
Earth wire
(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
diameter.
10mm
CAUTION
Power source cable and connecting cable must conform to the
Using cables with wrong may result in unit malfunction.
6. FINISHING WORK
NOTE
Indoor unit
● 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)
Tape
Position it so that the slit area faces upward.
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.
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.
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
Both liquid and gas service valves are fully open.
Earth leakage breaker Circuit breaker
Leakage current: 30mA,
Over current: 25A
0.1sec or less
Parts No.
SSA564A136A
mentioned below.
<Connecting cable> <Wire end>
30mm or more
10mm
40mm or more
of terminal block and wire
Round crimp-type terminal
Sleeve
mentioned in the manual.
Indoor unit
unit D unit D
D
unit C
unit C
Outdoor
C
unit
B
unit B unit B
A
unit A
unit A Piping
Wiring
(4)
Insulation pad Connecting cable
Liquid pipe
Drain hose
to the terminal block.
2.Connecting cable
(1) Remove the service cover and the terminal cover.
(2) Connect the cables according to the instructions and
(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>
Power
source
Circuit Earth
breaker leakage
breaker
NOTE
Locations where relative humidity exceeds 70%, both liquid and gas pipes need to be dressed with 20mm
or thicker heat insulation materials.
D
Outdoor
C
CAUTION
unit
B
A
• 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
Gas pipe
cover securely. Water may enter the unit
if service cover is not installed properly,
Tape
resulting in unit malfunction and failure.
CAUTION
Insulation
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.
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.
17
- -
'17 • SCM-T-225
given below.
Outdoor uni t
unit A unit B unit C unit D
1 2 3 1 2 3 1 2 3 1 2 3
N L
1 2 3 1 2 3 1 2 3 1 2 3
unit A unit B unit C unit D
Indoor unit
View of Terminal block unit C unit D
POWER
unit A unit B
source
Cable
clamp
Power
source
cable
Gauge manifold
Service port
Charge hose
RPC012A920C
Connecting
cable
Cable
clamp
Connecting
cable
Pipe
assembly
Screw
Clamp