assemblies, as marked, from damage due to excessive
to the terminal side of the plug-in modules for testing
Tables 6-1, 6-2, and 6-3 describe the various oper-
Switch and Fuse Panels.-- The switch and fuse
ating controls (switches) and indicators located on the
panel in cabinet 1 contains alarm-type indicating fuses,
two switch and fuse panels.
equipment enable (in-service)/disable (out-of-service)
switches, the attendant's cabinet enable switch, and the
Circuit Card Cages.-- The circuit card cage in
emergency cut-in selector switch. Figure 6-19 is an
cabinet 1 of both the 100-line and 150-line switchboards
illustration of the switch and fuse panel for the 100-line
contains six circuit card assembly shelves. The cage in
switchboard located in cabinet 1.
cabinet 2 of the 100-line switchboard contains three
circuit card assembly shelves, and the cage in cabinet 2
The switch and fuse panel in cabinet 2 contains
of the 150-line contains five assembly shelves. Each
alarm-type indicating fuses, equipment enable/disable
circuit card shelf accommodates 14 plug-in modules.
switches, ringing generator transfer switches, traffic
The modules consist of integrated circuit (IC) packages
and all trunks busy registers, and alarm indicator lamps.
mounted on circuit card assemblies.
Figure 6-20 is an illustration of the switch and fuse panel
for the 100-line switchboard located in cabinet 2.
CROSSBAR SWITCHES.-- The standard
coordinate-type crossbar switch is used as the
The alarm-type indicating fuses located on the pan-
basic switching unit in the switchboard. This
els protect the various switchboard circuits and/or
Figure 6-20.--Switch and fuse panel for the 100-line switchboard, cabinet 2.