Making Ground And Power Connections - Symmetricom SSU-2000e User Manual

Chapter 2 Installing the SSU-2000e

Making Ground and Power Connections

Figure 2-1. Equipment Mounting Cabinet
To install the SSU-2000e in the mounting rack:
1. Attach a mounting bracket to each side of the chassis by aligning two columns
(three holes per column) of the bracket with the holes on the side of the chassis.
Use appropriate screws for attaching the mounting bracket. Ensure that both
brackets are attached at equal distances from the front of the unit.
2. Mount the SSU-2000e to the front of the rack rails with the appropriate number of
screws and washers for the rack.
Recommendation: To aid in viewing and when connecting cables,
install the SSU-2000e chassis at eye level whenever possible.
Making Ground and Power Connections
Making Ground Connections
After installing the SSU-2000e in a suitable equipment cabinet, connect the chassis
to a proper earth ground. This can best be accomplished by running a cable from
the frame ground lug and connecting it to the equipment cabinet. Keep this cable as
short as possible. Frame ground connections are made through two M5 studs
labeled FG located next to the power connectors in the upper right and left corners
of the shelf. Frame and logic ground are connected together on the backplane to
form a multi-point ground system.
Using a digital voltmeter, measure between the ground and chassis and verify that
no voltage potential exists between them.
Making Power Connections
The SDU-2000e Main shelf has redundant –48/60 VDC power input connections,
labeled J101 A-BUS and J102 B-BUS. The A-BUS connection is a DA3W3P
connector located in the upper left corner and the B-BUS connection is another
DA3W3P connector located in the upper right corner.
Refer to Figure 2-2
2 of each connector is –48/60 VDC and pin 3 is the Return. The –48/60 VDC power
inputs have feed-through Pi-filters on each line through the front panel and DC
Isolated from Frame and Logic ground. The power return connections are
connected to Frame and Logic ground. Both the A-BUS and B-BUS power are fed
to the individual module slots through the backplane.
62 SSU-2000e User's Guide
for power connections. Pin 1 of each connector is not used. Pin
12713140-002-2 Revision E – October 2006