The plug-in power supply card 751324 is powered from a +24 Vdc source and provides -24 Vdc power to the 5-card Shelf or the 8-card Shelf. Since Teleline equipment cannot operate from +24 V, it requires -24 V referenced to ground.
Two Plug-in Power Supply Cards may be installed in the 5-or 8-card Teleline shelf for redundancy. Each card is capable of providing the power required by a fully loaded shelf.
When two cards are available, the load is shared by the two cards. If one power supply card fails, the other power supply card takes over the full load without interruption of power.