Power Supply Unit Load Requirements; Unit Load Calculation Rules - Lucent Technologies MERLIN LEGEND Release 6.0 Pocket Reference

DEFINITY ECS Release 6
System Description Pocket Reference 555-230-211
Power Supply Unit Load

Power Supply Unit Load Requirements

Unit Load Calculation Rules

Installed
Mode Modules
Hybrid/PBX,
Modified Key,
or
Behind Switch
Square Key
4 or fewer
or
Behind Switch
Square Key or 5 or more
Behind Switch
* The 391A1 and 391A2 power supply units generally support 6 modules of
any type in Hybrid/PBX mode. However, if all 6 carrier slots meet the
following conditions, the unit load total may exceed 54 and auxiliary power
may be required:
Only MLX or analog multiline station modules are installed.
More than 45 MLX-20L or 34-button analog multiline telephones are
installed.
The 391A3 power supply has a maximum rating of 75 unit loads. Use this
power supply in place of a 391A1 or 391A2 on systems where unit loads
will exceed 54.
Auxiliary Power Units cannot be used with the 391A3 power supply.
† The 391A1 power supply unit generally supports 4 modules of any type in
Square Key mode.
Calculation
Not required
*
6
Not required
†
Use the "Unit Load Rating of
System Modules" table and
instructions below to determine
the estimated unit loads (ULs):
If the ULs < 75 and the
—
391A3 power supply is used,
then no calculation is
required. If a 391A1 or 391A2
power supply is used and the
ULs > 54, then an auxiliary
power supply is needed or
replace the power supply
with a 391A3.
If ULs > 75, reconfigure the
—
system so that the total ULs
do not exceed 75 per carrier.
Issue 2
January 1998
Page 86