5.10.3 About wiring layout
Fig. 5-20
Some power equipment may have an
inverted phase or intermittent phase (such as
a generator). For this type of power sources,
a reverse-phase protection circuit should be
installed locally in the unit, as operating in the
inverted phase may damage the unit.
The power cord may produce
electromagnetic interference so you should
maintain a certain distance from equipment
that may be susceptible to such interference.
Indoor units or MS box in the same system
must be powered by the same power supply,
in order not to damage the system.
Power supply for the indoor or MS box should
separate from outdoor units.
For systems with multiple units, make sure a
different address is set for each outdoor unit.
NOTE
Power cords and communication wiring must
be laid out separately, they cannot be placed
in the same conduit. Use a power supply
conduit to isolate if the current of the power
supply is less than 10 A. If the current is
greater than 10 A but less than 50 A, the
spacing must exceed 500 mm at all
times.otherwise, it may lead to
electromagnetic interference.
Arrange the refrigerant piping, power cords
and communication wiring in parallel, but do
not tie the communication lines together with
the refrigerant piping or power cords.
Power cords and communication wiring
should not come in contact with the internal
piping so as to prevent the high temperature
piping from damaging the wires.
Once the wiring layout is completed, close
the lid tightly to prevent the wiring and
terminals from being exposed when the lid is
loose.
NOTE
5.10.2 Wiring layout (overview)
Wiring layout comprises of the power cords and
communication wiring between the indoor, MS box and
outdoor units. These include the earth lines, and the
shielded layer of the earth lines of the indoor units in the
P, Q, E communication line. See below for an example of
a wiring layout.
a
5.10.4 Communication wiring layout
5.10.4.1 Wiring mode
Fig. 5-21
Communication wiring of indoor unit: The P
,
Q, E
communication line should be connected in a chain
starting from the outdoor unit to each MS box, and then
from the MS box to each indoor unit. In the last indoor
unit, connect a resistor of 120 ohms between the P and
Q terminals. The correct and wrong connection methods
are demonstrated below:
MS box
Master
unit
P Q E
Indoor unit
Indoor unit
P Q E
P Q E
P Q E
Communication wiring of outdoor unit: The H1
,
H2, E
communication lines of the outdoor unit should be
connected in a chain starting from the master unit to the
last slave unit, as shown below.
P Q E
P Q E
P Q E
P Q E
P Q E
Master
unit
Slave
unit 1
Slave
unit 2
MS box
H1 H2 E
H1 H2 E
b
b
b
b
b
b
b
b
j
d
j
j
j
a
c
c
c
g
e
f
h
h
i
i
i
i
i
d
j
b
b
h
k
k
g
m
m
Three-phase power supply (with earth lines and
leakage protection)
Power distribution box
Power supply terminal of outdoor unit
Single phase power supply (with earth lines and
leakage protection)
H1, H2 and E communication wire(with shielded layer
) between outdoor unit and outdoor unit
P,Q and E communication wire(with shielded layer)
between outdoor unit and MS box
Earth line
Outdoor unit
Indoor unit
Main switch (with leakage protection)
MS box
P, Q and E communication wire (with shielded layer)
between MS box and Indoor unit
b
c
d
e
f
g
h
i
j
k
m
Indoor unit
Indoor unit
MS box
MS box
MS box
Indoor unit
Indoor unit
P Q E
P Q E
Indoor unit
Indoor unit
P Q E
P Q E
P Q E
P Q E
MS box
Master
unit
P Q E
Indoor unit
Indoor unit
P Q E
P Q E
P Q E
Indoor unit
Indoor unit
MS box
Indoor unit
Indoor unit
P Q E
P Q E
Indoor unit
Indoor unit
P Q E
P Q E
P Q E
P Q E
The indoor units under the different MS box,the communication
wiring can not connect.
26
