RA55 032615
1
SECTION 1 - DESCRIPTION
1.1
GENERAL
The Kepco Model RA 55 Rack Adapter (Figure 1) is designed for the installation of Kepco MST
Series Power Supplies into a standard 19-inch rack. Each rack adapter can accommodate a
maximum of nine power supplies, or eight power supplies and a communication bus controller
(Kepco Model MST 488-27) installed in slot 9. The RA 55 has a removable plate at the rear of
slot 9 to allow for the controller connector.
FIGURE 1. KEPCO MODEL RA 55 RACK ADAPTER
1.2
ELECTRICAL
The rack adapter contains a PCB backplane whose connectors facilitate hot-swapability. Dual
a-c input terminal blocks (J10 and J11) on the backplate assembly (Figure 2) distribute input
power to nine PCB-mounted a-c input/control bus power connectors (P1 - P9) as shown in
Figure 4. Terminal block J10 provides input power slots 1 through 4; terminal block J11 pro-
vides input power to slots 5 through 9 Two-wire IEEE 1118 control bus data is supplied to the
nine a-c input/control bus power supply connectors via two 9-pin (six pins are not used) con-
nectors, J12 and J13 on the backplate assembly. The utilized pins of the two IEEE 1118 con-
trol bus connectors are paralleled, facilitating "daisy chain" control bus configurations. A
shield connection is routed to connector P9 for grounding within the controller when a control-
ler is installed; otherwise this connection is not used.
