Toa N-8020MS - Manual (Page 4)

4.2. The Type of Cables
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.
• 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 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
4.3. Relations Between Core Diameter of Cable and
Maximum Cable Length
Referring to the following chart as guidelines, design the
distance between the Exchange and stations so that loop
resistance value becomes 170 Ω or less.
4.4. Mini-Clamp Connector Connection
Mini-clamp connectors for line terminals are supplied with the
N-8000EX Exchange.
Connect the mini-clamp connector to a cable using a
commercially available tool (pliers).
Step 1. Cut off two-cable ends in equal length, and insert
them securely to a cover section (transparent side) of
the mini-clamp connector.
Note
Insert the cable without stripping the cable jacket.
Cover (transparent side)
Cable
Step 2. With a pair of pliers, lightly pinch the mini-clamp
cover and, after ensuring that the cable is securely
inserted, firmly squeeze on the cover.
Note
Squeeze on the mini-clamp cover until it is correctly
locked.
Step 3. Insert the wired connector (plug) into the exchange's
connector (socket) until it locks into place.
N-8000EX Rear panel
Conductor
diameter
(mm)
ш 0.4
ш 0.5
ш 0.65
ш 0.9
Maximum cable length between the
Exchange and station
(Assuming that the loop resistance is 170 Ω.)
570 m
900 m
1.5 km
2.9 km
Loop
resistance
(Ω/km)
295
187
113
58
133-06-262-9B
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