Mitsubishi Electric M Series Manual page 574

MULTI SYSTEM Inverter Heat Pump
7. Electrical work
Warning:
In case of A-control wiring, there is high voltage potential on the S3 terminal caused by electrical circuit design that has no electrical insulation between power
line and communication signal line. Therefore, please turn off the main power supply when servicing. And do not touch the S1, S2, S3 terminals when the power
is energized. If isolator should be used between outdoor unit and branch box/indoor unit and branch box, please use 3-poles type.
Caution:
After using the isolator, be sure to turn off and on the main power supply to reset the system. Otherwise, the outdoor unit may not be able to detect the branch
box(es) or indoor units.
WIRING SPECIFICATIONS
(OUTDOOR-BRANCH BOX CONNECTING CABLE)
Cross section of cable Wire size (mm
Round
2.5
Flat
2.5
Flat
1.5
Round
2.5
*1 : Power supply cords of appliances shall not be lighter than design 60245 IEC or
227 IEC.
*2 : In case that cable with stripe of yellow and green is available.
*3 : In case of regular polarity connection (S1-S2-S3), wire size is 1.5 mm
*4 : In case of regular polarity connection (S1-S2-S3).
*5 : In the flat cables are connected as this picture, they can be used up to 55 m.
Be sure to connect the outdoor-branch box/indoor-branch box connecting cables directly to the units (no intermediate connections).
Intermediate connections can lead to communication errors if water enters the cables and causes insufficient insulation to ground or a poor electrical contact at the
intermediate connection point.
C-572
Power supply
3 poles isolator (Switch)
Isolator (Switch)
S1
Outdoor unit S2
S3
) Number of wires
2
Clockwise : S1-S2-S3
3
* Pay attention to stripe of yellow and green
Not applicable
3
(Because center wire has no cover finish)
4 From left to right : S1-Open-S2-S3
Clockwise : S1-S2-S3-Open
4
*Connect S1 and S3 to the opposite angle
.
2
S1 S1
Branch
S2 S2
box
S3 S3
Polarity
S1 S2 S3
*6 : Mentioned cable length is just a reference value.
It may be different depending on the condition of installation, Humidity or materi-
als, etc.
S1
"A-control"
S2
Indoor unit
S3
L (m)*6
(50)
Not applicable
(45)
(55)
(3C Flat cable 2)
M series
*2
*5
*3
*4