RA55 032615
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nected to safety ground in order to ensure proper grounding of the MST power supplies
and MST 488-27 Controller (when installed).
•
Terminals L (Line Phase) and N (Neutral)
are connected to the input power entry con-
nectors. J10 provides a-c power to connectors P1 through P4; J11 provides a-c power to
connectors P5 through P9. Connectors J10 and J11 are independent of each other,
allowing the user complete flexibility in wiring for common or redundant input power con-
figurations.
The following standard wiring configuration is recommended by Kepco as being compliant with
applicable national and international safety standards. Please consult local electrical codes for
wire current ratings and other specific requirements:
•
Connect Terminal G of the RA 55 input power terminal block (J10, J11) to safety ground
•
Connect a separate wire pair from each side of the input power to the L/N terminal pair of
the input power terminal block (J10 for slots 1 through 4, J11 for slots 5 through 9).
•
Wire size is determined by the maximum rated source current for each MST power sup-
ply and the number of MST modules installed. Operation below 100V rms can result in
source current in excess of 15A at terminal block J10 or J11. For this reason Kepco rec-
ommends use of #14 AWG wire (minimum) in fully populated systems. For lower system
power configurations, smaller wire can be used; contact Kepco Applications Engineering
for assistance.
2.2
LOAD CONNECTIONS
Load connections to the RA 55 are achieved via the nine individual connectors (J1 - J9) located
on the backplate assembly directly behind each mounting position (see Figures 2 and 4). Mating
connectors (assembly required) are supplied (see Figure 6).
NOTE
REGARDLESS OF OUTPUT CONFIGURATION, OUTPUT SENSE LINES OF
MST POWER SUPPLIES MUST BE PROPERLY CONNECTED FOR OPERA-
TION (REFER TO MST INSTRUCTION MANUAL).
2.3
CONTROL SIGNAL CONNECTIONS
Access to the IEEE 1118 communication control bus for each power supply is provided via two
9-pin D-subminiature type connectors (J12 and J13) on the backplate assembly (see Figures 2
and 4). Two pins of each connector are used for the 2-wire control bus; the third pin is utilized
when a controller is installed in slot 9, allowing the shield to be grounded within the controller.
2.4
SLOT 9 CONFIGURATION
The unit is shipped with slot 9 configured to accept an MST power supply. To install a controller
in slot 9, remove J9 connector plate by removing four screws at the backplate assembly (see
Figure 2).
