Haier YR-H 71 Service Manual page 52

Installation and Debugging
Installation Methods
Fix detector by means of two screws hanging methods, and distance
between screws see (right figure).
1. Realization, installation, wiring and power distribution of a system only
using two-unit switchover function are much more easier, after finishing
installation of two units, connect detector to the remote control interface
of the air conditioner computer board, set detector as two-unit switchover
working mode and set two-unit switchover time as required.
2. It must form a complete set of documents (project layout for group control network, installation and
construction records for group control network, debugging records for group control net, maintenance
and repair records for group control network) for group control network of Haier commercial air
conditioner long distance system (hereinafter for short as: group control network) from layout design,
installation, debugging to after service, and file all for future reference.
3. Layout design of group control net woek shall be finished in advance, including: (1) compositions of
group control network system and quantities controlled; (2) selection type of air conditioner,
installation place, power distribution and wiring manner and connection to detector; (3) installation
place of detector, allocation of unit address code, power distribution and wiring manner and
connection to group control bus; (4) installation and wiring of group control bus, length limitation of
bus, resistance matching of two ends of bus, and single point earth of bus shielding layer; (5)
installation place of central controller, allocation of unit address code, power distribution and wiring
manner.
4. Principles of layout design of group control net: (1) detector is essential part, to keep proper
responding speed and communication reliability, detector quantities carried by one central controller
shall not more than 64; (2) air conditioner must be a net air conditioner, installation must strictly
follow the installation and operation instructions shipped with the unit, and confirm that power
blackout compensation function of local air conditioner has been cancelled when debugging; (3)
suggest that do not use two-unit switchover function of detector in the case of high load, i.e. suggest
that do not use one detector to load two air conditioners when detector forming group control net,
otherwise temperature difference control may be affected. If it is necessary to install two-unit
switchover function for group control net, air conditioners with same type and half installation
distance of that of normal installation are required; (4) installation place of detector shall not too far
away from air conditioner, not exceed the wiring length; (5) unit address code of detector shall be
strictly allocated in a sequence from small one to big one, and set continuous unit number; (6) for
power distribution of detector, the power distribution line and communication line shall not be too
close from each other or in the same wiring channel, and no other special requirements; (7) for
connection between detector and group control bus, not allowed to connect branch line from the
group control bus; (8) shielding line of communication line between detector and air conditioner and
the shielding line of communication bus between detector and central controller shall be shorted; (9)
wiring and power distribution line of the group control bus shall not be too close from each other or
in the same wiring channel, and others may refer to wiring requirements of building autocontrol
system; (10) limit the total length of group control bus to 1000 meters; (11) at both ends between
Bus A and Bus B connect a metallic membrane precision resistance of 100 or 120 ohm respectively; if
needed (12) single point earth for bus shielding line, suggest to be arranged in the middle of
communication bus, close to central controller;
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