Hitachi YUTAKI ATW-YCC-03 Installation And Operation Manual page 44

◆ H-LINK connection
The YUTAKI units, YUTAKI CASCADE CONTROLLER and outdoor units are interconnected via bus
called H-LINK II, consisting of 2 non-polarity cables and accepting lengths of up to 1000 m. All
YUTAKI and Outdoor units which are controlled by the same YUTAKI CASCADE CONTROLLER unit
must be connected at the same H-LINK II line:
OU n OU 2
OU n
Setting of End Terminal Resistance
When connecting outdoor units to an H-LINK II line, it is necessary to set the end terminal
resistance as active (DSW5-1 ON) in only one of the units. Pin 1 of DSW5 is factory set to ON in all
the outdoor units. Therefore, when connecting multiple outdoor units to an H-LINK II line, please
check and make sure that only one of the units has pin 1 of DSW5 set to ON, and the rest of the
units have pin 1 of DSW5 set to OFF.
The H-LINK II connection must be done as it is shown in the figure below:
YUTAKI unit
Terminal Board 2
• The H-LINK wiring system requires only two transmission cables that connect the indoor unit
and the outdoor unit.
• Use twist pair wires (0.75 mm²) for operation wiring between outdoor unit and indoor unit. The
wiring must consist of 2-core wires (Do not use wire with more than 3 cores).
• Use shielded wires for intermediate wiring to protect the units from noise interference. Total
H-LINK circuit length shall not exceed 1000m and a size in compliance with local codes.
• In the event that a conduit tube for field-wiring is not used, fix rubber bushes to the panel with
adhesive.
PMEN0581 rev.2 - 04/2023
OU 1
OU 2 OU 1
1
YUTAKI YUTAKI YUTAKI
2 n
......
YUTAKI CASCADE CONTROLLER
Terminal Board 2
ATW-YCC-03
YUTAKI YUTAKI
5
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