based on size of the power cable. Consult the National Electrical Code (NFPA 70) or Canadian
Standards Association (CSA 22.1) for maximum allowable capacity of cable size used.
Note that cable distance between stations as well as total cable length must be considered.
Table in this section will provide guideline for cable distance (length) and number of 24VDC
stations connected to it in parallel. This table is based on speech signal driving station speaker/
amplifier to produce full 12-watt output into an 8-ohm speaker. It is also assumed that stations
are spaced at equal distance from one another along the cable length. A speech signal has
less energy content then continuous sine wave signal so the average current draw per station
is less then sine signal.
MAXIMUM CABLE DISTANCE PER POWERLINE BRANCH
14AWG CABLE
12 AWG CABLE
10 AWG CABLE
8 AWG CABLE
N
umber
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T
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of
S
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S
TaTioNS
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1
4000ft
4000ft
6400ft
6400ft
10000ft
10000ft
16000ft
16000ft
2
2800ft
1400ft
4480ft
2240ft
7000ft
3500ft
11200ft
5600ft
3
2000ft
660ft
3200ft
1060ft
5000ft
1667ft
8000ft
2667ft
6
1200ft
200ft
1920ft
320ft
3000ft
500ft
4800ft
800ft
9
800ft
90ft
1280ft
142ft
2000ft
220ft
3200ft
356ft
The 24 VDC power connections are made at the 3-position terminal block JP1 mounted on
the motherboard in the station enclosure. Connect the black positive (+) 14 AWG conductor
of incoming and out going power cable to the + terminal of JP1. Connect white, negative
(–) 14 AWG conductor of incoming and out going power cable to the – terminal of JP1.
Connect the green/yellow the earth ground 14 AWG conductor to the GND terminal of the
JP1 terminal block.
c. Page Line and Party Line Connection.
SHOCK HAZARD
To avoid electrical shock, do not connect wires when power is applied.
All the channel line and page line connections are made at the L1 and L2 terminal blocks
mounted on the motherboard. The incoming and outgoing cable of multi-channel systems
have six, differently colored, 18 AWG, twisted pair conductors. One conductor of each twisted
pair is of solid color and the other has a stripe of the same color.
1. As shown in Figure 1, the page line connections are made to the L1 and L2 terminal blocks,
at the terminals marked L1 PAGE L2. Connect 18 AWG RED conductor of twisted pair
RED, WHITE/RED of the incoming and outgoing cable to L1 and conductor WHITE/
RED to L2 at location marked PAGE on the motherboard.
2. To make party line 1 connection, connect GREEN conductor of incoming and outgoing
cable’s 18 AWG twisted pair GREEN ,WHITE/ GREEN to L1 and
W H I T E /
GREEN conductor to L2 terminal at location identified as PARTY 1 between terminal
blocks L1 and L2.
3. For party line 2 connection, connect BROWN conductor of twisted pair BROWN, WHITE/
BROWN to L1 and WHITE/BROWN conductor to L2 terminal at PARTY 2. For party
line 3, connect ORANGE conductor of ORANGE, WHITE/ORANGE twisted pair to L1
and WHITE/ORANGE to L2 at PARTY 3. For party line 4, connect VIOLET conductor
-6-
