AT&T System 75, Wiring Diagram

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CHAPTER 3. EQUIPMENT ROOM DESIGN
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110PC1-900CT which is equipped with 36 female 50-pin
connectors. The connectors are mounted at the top of the
terminal block. This can be used if cable routing from the top is
desirable.
Distribution Field
The distribution field contains four distinct cross-connect areas:
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The purple field (port field) terminates 25-pair cables from the
switch. Each line circuit pack connects to one 66-type connecting
block or to one 25-pair row of the 110-type terminal block. One
25-pair cable is required for each line circuit pack.
Note: This is the case except for the 16 port analog line
circuit pack and the MET line circuit pack. The 16-port
analog line circuit pack requires an adapter cable to connect
from one connector on the switch to two 25-pair connectors
on a 66-type connecting block/110-type terminal block. Two
MET line circuit packs require a concentrator cable to
connect from two connectors on the switch to one 25-pair
connector on a 66-type connecting block/110-type terminal
block.
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The yellow field (auxiliary field) terminates all 25-pair cables from
the auxiliary cabinet and the AP. The yellow field is located in the
lower right-hand corner of the distribution field.
The white field (station field) terminates the station wiring. The
white field indicates 3-pair station circuits (eight circuits per
25-pair cable) that are routed through a satellite closet.
The blue field (station field) also terminates station wiring. The
blue field indicates 3- and/or 4-pair station circuits (eight or six
circuits, respectively, per 25-pair cable). The fourth pair, of the
4-pair station circuit provides adjunct power from the
cross-connect field on an as-needed basis to terminals within 250
feet (wire length) of the cross-connect field.
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