Unit Loads

A cabinet can supply no more than 80 unit loads of 48 volt power (a unit load is defined as 44 mA). Unit loading is determined by the terminal connected to the port circuits. The

following table lists

unit loads for various terminals.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UNIT LOADS (Note)

 

 

 

 

 

 

 

 

 

EQUIPMENT

CIRCUIT

UNIT LOAD

 

 

 

 

 

 

PACK

PER PORT

 

 

 

 

 

 

 

 

 

 

 

 

2500 Voice Terminals

ZTN78

0.5

 

 

7101A Voice

Terminal

 

 

 

 

TN742

1.0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MET

Sets

 

TN735

1.0

 

 

 

 

 

 

 

 

5-Btn.

(7302H01D)

ZTN79

1.0

 

 

10-Btn. (7303 H01D)

 

1.0

 

 

34-Btn. (7305 H01D)

 

1.0

 

 

HFAI (7309 H01B)

 

1.0

 

 

 

 

 

 

 

BIS (7305 H03B)

ZTN79

1.50

 

 

BIS

w/display

(7305H04C)

ZTN79

2.00

 

 

 

 

 

 

 

34-Btn. Deluxe

ZTN79

2.0

 

 

(7305 H02D)

 

 

 

 

 

 

 

 

 

 

 

ZTN79

1.0

 

 

S102A Speakerphone

 

 

 

 

 

 

 

 

 

502A

Headset

Adapter

ZTN79

0.75

 

 

Asynchronous

Data Units

TN726

0.0

 

 

 

 

 

 

 

 

 

Tie

Trunks

 

TN760B

2.0

 

 

 

 

 

 

 

 

 

DID

Trunks

 

TN753

0.5

 

 

 

 

 

 

 

Emergency Transfer Unit

ZTN82/128

2 per ETU

 

 

 

 

 

 

 

 

Pooled

Modem

TN758

Zero Unit Loads but

 

 

 

 

 

 

 

maximum of two

 

 

 

 

 

 

 

TN758s/cabinet

 

 

 

 

 

 

 

allowed.

 

 

 

 

 

 

 

 

 

DXS

Selector

Console

Locally Powered

 

 

 

 

 

 

 

 

Note: Equipment not listed above (i.e., TN763, ZTN76, ZTN77) does not affect unit loading. Any voice terminal/adjunct combination requiring more than 2 Unit Loads must be locally powered. When a voice terminal is locally powered, it places no unit load on the cabinet. Specifically, a 34-Button Deluxe voice terminal equipped for speakerphone operation requires auxiliary power. In addition, any 34-Button Deluxe, BIS, or BIS with Display voice terminal equipped for headset operation requires auxiliary power.

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AT&T AT&T manual Unit Loads Note, Equipment Circuit Unit Load Pack PER Port, ZTN79 BIS, Dxs