AT&T System 75 Wiring Diagram page 105

CHAPTER 3. EQUIPMENT ROOM DESIGN
rounded up (for example: 2.4 = 2 cable slack managers and 2.5 = 3
cable slack managers required).
110-Type Hardware and Patch Cord Requirements
Table 3-D lists the amount of 110-type hardware required to provide 1-,
2-, 3-, or 4-pair distribution for the station wiring. The 110-type terminal
blocks are available in various sizes and the number of stations
connected to each block depends on the number of pairs that are run
per station.
Table 3-D. 110-Type Hardware Requirements
Available
Block Pairs
75
100
300
900
* 1- and 2-pair wiring is only possible for analog telephones that
are cross-connected using 110A-type hardware.
3-22
Station Wiring
1-Pair 2-Pair
Wiring*
Wiring*
75 36
100 48
144
300
432
900
4-Pair
3-Pair
Wiring
Wiring
24 18
32 24
72
96
216
288