AT&T MERLIN LEGEND Pocket Reference page 54

Power Supply Unit Load Requirements
(continued)
Unit Load Calculation Rules
Installed
Modules
Mode
5 or more
Square
Key/
Behind
Switch
*
Empty slots are not permitted between modules.
Page 50
(continued)
Calculation
Use the "Unit Load Rating of
System Modules" table and
instructions below to determine
the estimated ULs:
If ULs equal 54 or less, an
Auxiliary Power Unit 9024 is
not required.
If ULs exceed 54, use "Unit
Load Rating of System
Modules" table to determine
the actual ULs for the system.
If the actual ULs exceed 54,
try to exchange modules
between carriers to reduce the
ULs below 54.*
If the modules cannot be
exchanged to reduce the ULs
below 54, an Auxiliary Power
Unit 9024 is required.