H-Link Ii System; Features; Specifications - Hitachi RAS-2-HVNP Service Manual

4. Electrical wiring

4.5 H-LINK II system

The H-LINK II is the wiring connection system between units.
The H-LINK II wiring system only needs:
• Two transmission wires connecting each indoor and outdoor unit for a total of 64 refrigerant cycles.
• Connection wiring for all indoor and outdoor units in series.
C A U T I O N
The H-LINK II system cannot be applied to the models with the old cycle, nor to units with an old transmission.
4.5.1 Features
• The total wiring length is considerably reduced compared to traditional connections.
• Only one connection is required for the wiring between the indoor and outdoor units.
• The wiring connection of the complementary central control devices is easy.
N O T E
• CSNET WEB is a centralized control system which allows the installation to be controlled remotely. It can be
connected at any point of the local corporate network, or even via the Internet.
4.5.2 Specifications
A: outdoor unit.
B: indoor unit.
C: refrigerant cycle.
D: transmission cables.
E: refrigerant piping.
Cable features
• Transmission cable: 2-wire.
• Polarity of transmission cable: non-polar wire.
• Maximum number of indoor units that can be connected: 4 units per cycle and 160 units per H-LINK II system.
• Maximum wiring length: total 1000 m (including CSNET WEB).
• It is possible to increase the maximum wiring length up to 5000 m by using up to four PSC-5HR units.
• Recommended cable: shielded twisted pair cable, over 0.75 mm
• Voltage: 5V DC.
C A U T I O N
For the H-LINK II system it must be used twisted shielded pair cable or shielded pair cable.
101
SMGB0079 rev.0 - 01/2013
Outdoor unit
Indoor units
A refrigerant cycle
Transmission cables
Refrigerant piping
(Equivalent to KPEV-S).
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