AT&T System 25 - Manual (Page 159)

INSTALLATION
Customer-provided paging equipment can also be connected to ZTN76 or
ZTlN77 CO trunk CPs. Connection to the system is made through the TAE
appearance of the Tip/Ring pair of the CO trunk CP (See Appendix A for
connection details). A paging equipment interface kit D-181900 consisting of
a Universal Telephone Access Module (UPAM) and a -48 VDC power supply,
PRS-48, is required unless all of the following conditions exist:
●
Paging equipment is FCC registered.
●
Paging equipment does not require a contact closure for proper
operation.
●
A trunk interface is provided.
If kit D-181900 is required, make connections using 4-pair inside wiring as
listed below (Figure 2-59):
1. Connect UPAM chassis ground to building ground.
2. Connect UPAM terminals PT and PR to paging equipment.
3. Connect UPAM terminals +24/48 and -24/48 to respective PRS-48
power supply terminals +48VDC and -48VDC. For ZTN76 ground
start CP only, connect +48VDC to System 25 system ground which
appears on the TAE block (Appendix A).
4. Connect UPAM terminal R to trunk CP ring lead appearing on TAE
block.
For ZTN76 ground start CP connect UPAM terminal T to UPAM terminal N.O.
and connect UPAM terminal COM to trunk CP tip lead appearing on TAE
block.
For ZTN77 loop start CP connect UPAM terminal T directly to trunk CP tip
lead appearing on TAE block.
If kit D-181900 is not required, use 4-pair inside wiring and connect paging
equipment directly to trunk CP tip and ring leads appearing on TAE block.
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