AT&T System 85 manual Adjunct Power

ADJUNCT POWER

One of these power supplies must be used for each voice terminal equipped with one or more adjuncts. Each of these power supplies (except the 95B1) has a maximum cable distance of

250 feet (76 m) between the power supply and the adjunct(s). The maximum cable distance for the 95B1 is 150 feet (45m). Voice terminal adjuncts and modules are not operational during interruptions of commercial AC power unless their power supplies are also powered through standby power of other essential AC power service.

The 329A and 346A power supplies clustered in a satellite closet are normally mounted on AC power strips. Power to these strips is provided from a dedicated 120 volt AC, 60-Hz, 20-ampere circuit breaker and feeder either directly or through a 543A telephone power unit. The 543A unit provides an inductive filter to limit inrush current on the feeder. It comes equipped with an AC power cord which plugs into the dedicated feeder and provides four receptacles for AC power strips.

The 945 bulk power system is usually rack mounted and is intended to be located in an equip- ment room or satellite closet. It is optionally made up of the following components:

945-1 bulk power supply unit

945-2 battery reserve unit

945-3 system enclosure, equipped with one or two 945-1 and/or a 945-2

945-4 single enclosure for 945-1 unit

Several power supplies and connection schemes are available for providing auxiliary adjunct power when it is required. Regardless of its source, auxiliary power is introduced into a pair of spare leads in the individual voice terminal’s line, at some wiring interface. The auxiliary power is fed into the terminal on the mounting line cord. From the terminal, power is distributed to the adjunct(s). An auxiliary power source is usually mounted in a satellite closet or adjacent to the voice terminal’s wall jack.

2-34