Service manual

System Overview 1-95
Major power components are described in the following sections except for the
power modules in the QBB and the power managers. For the main power
module, see Section 1.15.1, for the auxiliary power module, see Section 1.15.2,
for the H-switch, see Section 1.15.3, for the PSM, see Section 1.8.4 and Section
1.12, for the HPM, see Section 1.8.6 and Section 1.12, and for the PBM, see
Section 1.8.5.
Figure 1–43 is a block diagram of power distribution in a GS320 system. It
shows most of the major components that make up the power distribution
system. Power distribution from one component to the next is color-coded.
Cables used between subracks and system boxes maintain the color code as
well.
Color Codes
Color AC Input Box # Subrack # System Box #
Blue 1 (J1 – J3) 1 1
Green 1 (J4 – J6) 2 2
Orange 2 (J1 – J3) 3 3
Brown 2 (J4 – J6) 4 4
Note that diodes on the H-switch are used to “or” Vaux power so that whenever
any of the H7505 subracks receive AC power, the CSB and H-switch power
supplies receive Vaux.
Diodes for the OCP
Diodes on the subracks are used to “or” 48V so that whenever subracks
, ,
, or are on, the OCP is powered.
Diodes for the H-switch
Diodes on the H-switch are also used to “or” 48V so that whenever any of the
subracks are on, the H-switch is powered.
Diodes for the Cabinet Blowers
Diodes on the subracks are used to “or” 48V so that whenever subracks
or
are on, the blower in system cabinet 1
( ) is powered. The same is true for
subracks
or except that the blower in system cabinet 2 ( ) is powered.