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8.2. Type of Cable
The types of cables are to be determined according to the following conditions.
• Twisted pair wires (such as those used for electronic push-button telephone) are to be used for wiring between
the Exchange and the stations in principle.
• UTP category 5 Straight through cables with RJ45 connector are to be used for connecting to IP network.
• The number of cables pairs laid should be determined considering the possibility of future expansion of the
system.
• Outdoor wires should be used where wiring passes through inaccessible areas such as ceilings or under
floors where the maintenance is not performed. Indoor wires may also be used, however, in case where there
is no risk of deterioration due to exposure to heat, etc.
Note
Specifications related to each junction are as follows.
Mini-clamp connector (N-8000EX/8010EX line terminal)
Conductor diameter: ø 0.4 – 0.65 mm (AWG22 – 26), Solid wire
Outside diameter:
ø 1.05 mm or below
Clip terminal (E-7000TB)
Conductor diameter: ø 0.4 – 0.8 mm (AWG20 – 26), Solid wire
Outside diameter:
ø 1.5 mm or below
Removable terminal plug (N-8000EX Paging output)
Conductor diameter: ø 0.5 – 2 mm (AWG12 – 24), Solid wire/Stranded wire
8.3. Relations Between Core Diameter of Cable and Maximum Cable Length
Refer to the following table as guidelines when designing the distance between the Exchange and stations so
that loop resistance value becomes 170 Ω or less.
Conductor diameter
(mm)
Loop resistance
(Ω / km)
Maximum cable length between the Exchange and station.
(Assuming that the loop resistance is 170 Ω)
ø 0.4
295
570 m
ø 0.5
187
900 m
ø 0.65
113
1.5 km
ø 0.9
58
2.9 km
