AT&T MERLIN 3070 Administration Manual page 13

Addition of the Expansion Unit changes the Model 1030 control unit to a Model 3070 control unit and increases overall
system capacity to 30 lines and 70 voice terminals. The unit can accommodate:
The second Power Module is required for systems with more than 20 lines or more than 60 voice terminals. The Expan-
sion Unit also has two additional module slots for future use.
NOTE: If you add an Expansion Unit to a system configured for 15 outside lines and 20 voice terminals, you must remove
the Line Module from slot 11 and replace it with a Voice Terminal Module. This returns your system to the standard con-
figuration of 10 outside lines and 30 voice terminals. You can then insert modules into the appropriate slots in the Ex-
pansion Unit.
If Expansion Unit slots 17, 18, 21, 22, and 23 are empty, the power switch on the first Power Module (slot 16) must be
set to off (left). If modules are inserted in any of these slots, the power switch must be set to On (right).
If Expansion Unit slots 19, 20, and 24 are empty, the power switch on the second Power Module (slot 27) must be set
to Off (left). If modules are inserted in any of these slots, the power switch must be set to On (right).
10
Up to two Power Modules
Up to four Line Modules
Up to four Voice Terminal Modules
EXPANSION UNIT FOR MODEL 1030