I/O Adapter Panels; Making Ground And Power Connections - Symmetricom SSU-2000 User Manual

Chapter 2 Installing the SSU-2000

Making Ground and Power Connections

I/O Adapter Panels

The procedure for attaching the four types of I/O adapter panels to the rack are
identical. The location of the I/O adapter panels is limited only by the length of the
interconnecting cable. Input adapter cables are restricted to one meter. Output
adapter cables are available in lengths from one to two meters in increments of
0.1 meter; see
1. The I/O adapter panels may be mounted flush to the top or bottom of the shelf.
Use suitable screws for attaching the I/O adapter panel. Ensure that both
brackets are attached at equal distances from the front of the unit.
2. Mount the panels to the front of the rack rails with four screws and washers.
Recommendation: Although I/O adapters may be located as
necessary, Symmetricom recommends that you mount the Input I/O
adapter panels above the shelf to accommodate the shorter cable
length; mount the Output I/O adapter panels below the shelf.
Making Ground and Power Connections
The SSU-2000 shelf has redundant -48VDC power input connections labeled
A-BUS and B-BUS. The A-BUS connection is a 2-position #6 terminal block in the
upper left corner of the rear panel, and the B-BUS connection is a 2-position #6
terminal block in the upper right corner of the rear panel. The terminal positions are
labeled –48V and RTN. The –48V side of each bus is fused with a 5 Amp fuse. The
–48V power inputs are DC Isolated from frame ground and logic ground. Both the
A-BUS and B-BUS are fed to the individual module slots via the backplane. Refer to
Figure 2-4 for a view of the SSU-2000 rear panel.
Caution: For continued fire protection, replace fuse with specified
type and rating. Fuse: GMT-5 (5A @ 60vDC).
This unit must be grounded.
Refer all servicing to qualified personnel.
Caution: To avoid equipment damage, ensure that the power
terminal covers are installed after connecting the –48V power.
Caution: To provide proper I/O connector grounding, ensure that
when removing or installing Summer Output connectors that all
screws are tightened securely.
64 SSU-2000 User's Guide
Chapter 9, Hardware Configuration Guide, for part numbers.
12713020-002-2 Revision F.01 – January 2007