Figure 6-20.--Switch and fuse panel for the 100-line switchboard, cabinet 2.

assemblies, as marked, from damage due to excessive

to the terminal side of the plug-in modules for testing

current.

and troubleshooting.

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.

6-21