7. Cable Installation
7-1 The Type of Cables
Wire type, number of wire pairs and number of individual wires are
to be determined for individual sections of the wiring system ac-
cording to the guidelines set out below.
Twisted paired cables (such as those used for key telephones)
are to be used for wiring between the station and the intermediate
or indoor terminal board.
As a rule, private branch cables are to be used for wiring between
indoor terminal boards, intermediate terminal boards, main
terminal boards, etc.
Indoors, the number of cables that can be run through a conduit
is, as a rule, less than 200 pairs.
Outdoor wires should be used where wiring passes through inac-
cessible areas such as in ceilings or under floors. Indoor wires may
also be used, however, in cases where there is no risk of deteriora-
tion due to exposure to heat, etc.
The number of cable pairs laid should be determined considering
the possibility of future expansion of the system.
The following chart is provided to give an actual example of the
wiring plan within an installed system.
Exchanges
(EX-610/620)
Terminal
Boards
(BX-610/620)
Main
Terminal
Boards
Intermediate
Terminal
Boards
Secondary
Terminal
Boards
Stations
(HF-600M
etc.)
YR-810
Station
Speaker
Amplifier (s) for Paging
1. Junction
Cable (2-wire, for stations)
2. Junction
Cable (4-wire, for paging)
3. Private
Branch Cable (Multi-core cable)
Make sure to connect quad pairing when using a
multi-core cable.
4. 2-Wire
Cable
Never use a cable of 4 cores or more which is not
paired or quad-paired for connection to stations.
Note:
Since hardware to connect the cable to the terminal board BX-610 or BX-620 is
provided, there is a limit to the diameter of cables that can be used to connect the
terminal board BX-610 or BX-620 and the main terminal board, and this limit
must be taken into consideration when planning wiring of the system. The diam-
eter must be between 0.41mm (0.016") and 0.79mm (0.031").
7-2 Core Diameter versus Transmission Distance
Use appropriate cables according to the following table that shows
the relationships between core diameter and transmission distance.
18
20
22
24
1.02
(40.30)
0.81
(31.96)
0.64
(25.35)
0.51
(20.10)
4.6
(15,000)
3.5
(10,000)
2.5
(8,200)
1.5
(4,900)
Core
Diameter
mm (mils.)
Service
Distance
km
(ft)
YR-801
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