7-3 Wiring
1. General Information
Wiring should be done independently of public telephone lines.
Otherwise the EXES-6000's line (+30 dBm) can cause cross-talk in
the telephone line.
Wiring conduit is often installed underground or embedded in
building structures such as walls and floors, so care must be taken
to draw up a wiring plan that has ample reserve for future exten-
sion of the system and that can be adapted to future remodelling
or expansion of the building it is housed in. Wiring systems must
be planned with ample wires and conduit and with provision for
additions to the system.
Do not connect an unused cable to a connection cable between
the exchange and the station.
Exchange
Station
Not allowed
3. Piping
Where wiring is to be passed through a wall or the like, it should
be protected by a hard PVC or metal tube.
If the number of connecting wires between an indoor terminal
board and a station is small and the station's site is fixed so that
it will not be moved frequently, install a box at that site and pull
wiring through a metal or hard PVC tube as required by job or
ordinance.
Use a floor duct if the number of connecting wires is large and the
stations are likely to be moved frequently.
Station wiring which must be laid-across open areas of floor
should be protected by plastic or metal shields. (See drawing
below)
EXAMPLE:
Wall
Metal or hard PVC tube
2-Pin Jack
& Plug
Wire
protector
Box
Desk
Floor
Floor
Floor duct
When a multi-pair cable is used for connection, it must not be used
as a power cable or data transmitting cable for facsimile, etc.
2. Spacing
Since the working voltage of this system is low and the current
passing through it is small, there is no major safety problem involved
in the wiring.
However, since interference due to contact with other indoor wiring
can cause wire damage, leakage, and other problems, spacing should
be given close consideration when the small-current wiring of this
system is laid close to other indoor wiring, particularly AC wiring.
The following chart lists spacing standards to be followed in respect
to typical causes of interference.
Wire protector
Plastic or
Aluminum
Station wirings
4 inches
Cause of Interference
Heating Pipe
Water Pipe
Radio transmitting
coaxial cables (CB and
other).
Telephone wire.
Radio/TV Antenna
coaxial cables & twin
lead. Ground cable.
Protected Heating
and Cooling Pipes.
Minimum
spacing
acceptable
without
extra
protection
15cm (6")
10cm (4")
30cm (12")
10cm (4")
Remarks
This minimum spacing
requirement should be
observed, since intercom
cable is vulnerable
to heat.
More spacing is required
where there is a risk of
induction.
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