Clear-Com CS-100 - Permanent Installations

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When calculating the maximum current drain, only two figures need
be considered; a maximum current drain of 40 ma in the RS-100A or MR-102,
and an average current drain of 130ma in the KB-100 or KB-lll. Thus, an
equation for maximum stations would be as follows:
x = Number Of RS-100A's + MR-102
1
s <40.
Y
= Number of KB-l 00 I s + KB- 111 IS < 15.
Therefore,
0.04X + 0.13Y ~ 2.0
2.2.3
CABLES
Where cable lengths greater than 500 feet are involved, the maximum
number of remote stations, depends on four factors; the current requirements
of each remote station, the length of the wire, the wire gauge, and the cable
capacitance.
In all instances, 2-conductor, shielded interconnecting cable
should
be used.
A. PORTABLE INSTALLATIONS: rubber-insulated and jacketed cable should
be used due to its superior strength and durability. Belden 8413 mini-
ature cable (24 gao stranded conductors) is usable up to 500 feet.
Belden 8412 (20 gao stranded conductors) is usable up to 5,000 feet.
B. PERMANENT INSTALLATIONS: Vinyl-insulated and jacketed cable may
be used; it costs less and is easier to pull through conduit than
rubber
insulated types. However, low capacitance cable must be used.
Belden
8762 (20 gao stranded conductors) is usable up to 500 feet.
Belden S'1rA (18 gao stranded conductors) is usable up to 5,000 feet.
NOTE: In systems where conduit is not used, and where equipment may
not -share a common ground, it may be necessary to run an additional
ground wire to tie chassis together. This may be accomplished with
Belden
8770 3-conductor shielded cable.
C. 2-CHANNEL PERMANENT INSTALLATIONS: Permanent systems can be
wired in one of two ways. First, Channel A and Channel B may be
routed to two distinct areas, for use by different people. Second,
both channels
may be routed together and brought to WP-2 wall plates
so the user can select either channel A or B. The second method can
be wired with two 2-conductor shielded cables or one multi-pair shielded
cable.
Cables equivalent to the Belden types may be used, so long as their
capacitance and wire gauge are comparable. Particularly in longer runs, it
is desirable to use cable which has low resistance (large diameter conductors)
and low inter-conductor capacitance.
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