Unit Load Rules - AT&T MERLIN LEGEND Release 3.1 System Planning Manual

Unit Load Calculation
A unit load is a measure of power (1.9 watts) used to determine the electrical load
that the following components have on each carrier's power supply:
Telephones and Adjuncts. Only the telephones and adjuncts that
connect to the analog and digital ports on the control unit require unit
load calculation. Do not include any equipment with its own power supply
in the unit load calculation.
Direct Inward Dial (DID) modules
Unit load and power requirements for a new system are computed automatically
when the equipment for the system is initially ordered. These calculations are
based on the assumption that each module is fully utilized, that is, all jacks are
used.
It may be useful to obtain more accurate calculations, for example, if the modules
are not fully utilized, if there is a change in the equipment, or if you suspect that a
particular carrier has more unit loads than the power supply can handle. You can
calculate the actual unit load using the worksheet and instructions in this
appendix.

Unit Load Rules

A general rule to follow is that if you can distribute the DID modules and telephone
modules equally across the carriers, you will prevent unnecessary drain on any
one carrier.
Also, depending on the system's mode, the rules vary. This section provides the
rules for calculating unit loads in various modes.
F
F–1
System Planning