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RA55 032615
SECTION 2 - CONFIGURING THE RA 55 RACK ADAPTER
CAUTION
RACK ADAPTER SHOULD BE MOUNTED AND FASTENED SECURELY TO RACK
BEFORE INSTALLING POWER SUPPLIES TO AVOID DISTORTION OF THE RACK
ADAPTER. (INSTALL POPULATED RACK ADAPTER ONLY IF BOTTOM OF RACK
ADAPTER IS FULLY SUPPORTED.) FAILURE TO OBSERVE THIS CAUTION MAY RESULT
IN MISALIGNMENT OF THE POWER SUPPLIES WITH THE RACK ADAPTER.
NOTES:
1.
Prior to installation of MST Power Modules, remove the two plates installed in slots 3 and 7
(see Figure 1) for support during shipping.
2.
If Rack Adapter is received with MST Power Modules already installed, each Power Module
is secured to the Rack Adapter with two shipping screws. These screws are accessible
from the bottom of the Rack Adapter, and must be removed before installing the Rack
Adapter, otherwise the MST Power modules cannot be removed from the Rack Adapter.
2.1
INPUT POWER
2.1.1
GENERAL
Interconnections between an a-c power source and a stabilized power supply, and between the
power supply and its load, are as critical as the interface between other types of electronic
equipment. If optimum performance is expected, certain rules for the interconnection of input
power source, power supply and load must be observed by the user. These rules are described
in detail in the following paragraphs. All interconnections are accomplished at the backplate
assembly (Figure 2). Refer to Figure 3 for RA 55 interconnections and input/output connector
pin assignments.
2.1.2
SAFETY GROUNDING
National and international safety rules dictate the grounding of the metal cover and case of any
instrument connected to the a-c power source. The instructions below suggest wiring methods
which comply with these safety requirements; however, in the event that the specific installation
for the power system involves differences with the recommended wiring, it is the customers
responsibility to ensure that all local electrical codes for safety grounding are met.
2.1.3
SOURCE POWER CONNECTIONS
CAUTION
THE RA 55 DOES NOT INCORPORATE ANY SAFETY INTERRUPT DEVICES. PROTEC-
TION OF INPUT WIRING REQUIRES USER-CONFIGURED SAFETY INTERRUPTS.
The backplate assembly of the RA 55 includes two 3-terminal terminal blocks (J10 and J11) to
allow for the connection of single-phase source power. Wires must be sized according to
expected current. Wire size range is 20-10 AWG; torque to 6 lb-in (0.6 N•M) maximum. The ter-
minals are labeled L, N, and G. Their functions are:
•
Terminal G (Ground)
is the safety ground connection for the RA 55. It is connected to
the RA 55 chassis and to the safety ground terminal of the input power connector for
each of the nine mounting positions via the PCB backplane. Terminal G must be con-
