AT&T System 75 Wiring Diagram page 259

CHAPTER 4. STATION WIRING
4.
Connect ST leads on the yellow emergency transfer row/connecting
block for each emergency transfer telephone to the ST terminal
appearance in the yellow trunk/auxiliary cross-connect field (see
Note).
Note: The ST terminal leads should be terminated on the
following pairs: 1, 4, 7, 10, 13, 16, 19, or 22 (the first pair of any
3-pair group).
Connect the ST leads from the terminal selected in Step 4 to the
5.
assigned terminal in the blue or white station distribution field.
6.
If ground start is required, connect two wires from the ground
terminals to the third pair of each emergency telephone appearance
on the yellow trunk/auxiliary row created in Step 4. Loop the wires
from the first appearance through to the last appearance if enough
ground terminals are not (Figure 4-36).
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