AT&T System 75 Wiring Diagram page 164

Equipment Room Hardware And Cabling Installation
Selecting Concentrator Cables For Use With 66-Type Hardware
WP-90929, List 2 and 4 concentrator cables can be used to connect the
switch cabinet to the 66-type connecting blocks in the purple field.
Jumper wires are then run from the connecting blocks in the purple field
to the connecting blocks in the green field to establish the correct 3-pair
modularity for the 1- and 3-pair trunks. Table 3-H shows switch port
appearances at the cross-connect field. Figures 3-53, 3-54, and 3-55
show the carrier connectors on the rear of the switch that connect to the
purple field.
Connecting Trunk Pairs to the Switch Cabinet Using Concentrator Cables
Figure 3-56 shows trunk pairs connected to the switch cabinet with
concentrator cables. To install the cables, proceed as follows:
1.
Connect B25A connector cables between the network interface and
sneak fuse panels.
2. Connect A25D connector cables from the sneak fuse panels to the
110-type terminal block/157B connecting block connectors in the
green field.
3. For 110-type hardware only, connect patch cords/jumper wires
from the terminal block in the green field to the associated terminal
block in the purple field.
4. For 66-type Hardware only, install bridging clips on the 66-type
connecting blocks, as required (see Note).
Note: The left half of the 66-type connecting block is
designated as part of the green field and the right half is
designated as part of the purple field.
5.
Connect the single-fingered end of the concentrator cables to the
110-type terminal block/157B connecting block connectors
associated with the purple row in Step 3/4.
At the rear of the switch cabinet, connect the other end (2/3-fingered
6.
end) of the concentrator cables to the appropriate carrier slots
(Figures 3-53, 3-54, or 3-55). Equipped carrier slots are identified on
the CSO. Mark the nomenclature strips above the carriers to
identify the equipped slots.
3-81