Service Manual

GSM-204-323
Circuit breaker module (CBM)
31st Oct 01
Tech. 4–34
Technical Description: Horizon macro outdoor
CONTROLLED INTRODUCTION
68P02902W02-A
Circuit breaker module (CBM)
CBM overview
The CBM provides circuit protection and manual isolation for the CTUs, SURF
and BPSMs. The CBM is located above the digital module shelf and below the
PSMs. The honeycomb casing permits cabinet ventilation through the module.
The CBM is connected to the backplane, providing isolator switches and
overload protection for equipment indicated on its front panel (see Figure 4-20).
View of the CBM
Figure 4-20 shows views of the CBM with circuit breaker buttons identified.
FRONT VIEW
BACKPLANE CONNECTOR
M4 MODULE ATTACHMENT
SCREWS
HANDLE-BAFFLE
ig.281.rh
6 CTUs (0 TO 5)
15 A2 A4 A
7 A
NOT USED SURF
NOT USED
BPSMs (A AND B)
7 A
Figure 4-20 Views of CBM with circuit breaker buttons identified