Hitachi RAS-10HRNM, Service Manual, Page: 101 / 482

4.4 Electrical wiring between indoor unit and outdoor unit
Connect the electrical wires between the indoor unit and the outdoor unit, as shown in next figure.
Double-check that the terminal for power source wiring (terminals “L1” to “L1”, “L2” to “L2”, “L3” to “L3” and “N” to “N” of
each terminal board: AC380-415 V) and the intermediate wires (Operating line: terminals “1” to “1” and “2” to “2” of each
terminal board: DC5 V) between the indoor unit and the outdoor unit coincide correctly. If not, some component will be
damaged.
Unit Name of Dip Switch Mark Setting Before Shipment Function
Outdoor
unit
Refrigerant cycle
DSW4
RSW1
For setting refrigerant cycle address of outdoor
unit. Set the DSW4 and RSW1 not to overlap
the setting of other outdoor units in the same
H-LINK system.
Indoor unit
Terminating
resistance
DSW5
For matching impedance of transmission
circuit, set the DSW5 according to the quantity
of outdoor units in the H-LINK system.
Refrigerant cycle
DSW5
RSW2
DSW5
RSW2
For setting refrigerant cycle address of indoor
units. Set the DSW5 and RSW2 corresponding
to the address of outdoor unit in the same
refrigerant cycle.
Indoor unit address
DSW6
RSW1
DSW6
RSW1
For setting indoor unit address. Set the DSW6
and RSW1 not to overlap the setting of other
indoor units in the same refrigerant cycle. (If not
set, the automatic address function is
performed).
N O T E
• Follow the local codes and regulations when performing the electrical wiring (field and equipment).
• Use twisted shielded pair wires for transmission wiring between the outdoor unit and the indoor unit and also
for the transmission wiring between the indoor units (in case of an H-Link connection). It can be also used
shielded pair wiring.
• Shield shall be connected to the ground only from one cable side.
• Do not use more than 3 ring cores to coil transmission wiring (in case of an H-Link connection). Core ring sizes
must be selected according to the national regulations.
Connect the transmission wiring to the units belonging to the same refrigerant cycle (the refrigerant piping and the
transmission wiring should be connected to the same indoor units).
Open a hole near the connection terminal of the power source wiring when multiple outdoor units are connected from one
single power source line.
N O T E
• If the refrigerant piping and the control wiring are connected to the units in the different refrigerant cycle, it will
cause an abnormal operation.
• Fix rubber bushes with an adhesive on the panel when a conduit pipe for field-wiring is not used.
The recommended breaker-switch sizes are shown in the table of electrical data and recommended wiring.
C A U T I O N
• Pay attention to the connection of the operating line. An incorrect connection will cause the failure of the PCB.
4 Electrical Wiring
93
SMGB0060 rev. 1- 12/2010
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