ADTRAN Total Access 3000 System Manual page 175

is recommended for frame ground connections so that frame grounds can be easily
distinguished from other power connections.
Each fan unit also requires a connection to frame ground. 16 or 18 AWG ground wire
following the same color scheme as the shelf should be used. The fan units should be
connected to frame ground using the same method as the shelves.
1.4 Timing Considerations
Different applications of the Total Access 3000/3010 shelf may have differing timing
requirements. To determine which of the clock inputs are required, consult the
Application Guide for your particular application or refer to the shelf installation
diagram if one has already been prepared.
1.4.1 Composite Clock
If a composite clock input is required, a wire run from the clock source to the bay must
be provided. Use a 22 AWG or 24 AWG shielded two-wire cable with drain (such as
AT&T P7 wire) for this run. Up to eight shelves may be daisy chained to a single
output from the timing source, so only one wire run from the timing source is required
for an installation of eight or fewer shelves. The clock wire should be routed to the
anticipated location of the first shelf in a multi-shelf installation. Inter-shelf clock
wiring is performed during the shelf installation procedure.
1.4.2 T1 Clock
If a T1 Clock input is required, a wire run from the clock source to the bay must be
provided. Use a 22 AWG or 24 AWG shielded two-wire cable with drain (such as
AT&T P7 wire) for this run.
1.4.3 Stratum 3E Clock
In a DSLAM configuration, a Total Access 3000/3010 Stratum 3E Clock module can
be used to provide an accurate, uninterrupted clock to the system if the external clock
source, typically a DS1 BITS clock, is lost. This functionality is known as "Stratum 3E
Holdover." The module has a double-wide faceplate and must be plugged into slot 1.
No additional wiring is necessary.
1.5 DSX Considerations
Depending on the system application, each shelf may require connections to the
DSX-1 cross connect and/or the DSX-3 cross connect.
1.5.1 DSX-1
The Total Access 3000/3010 shelf may be wired to a DSX-1 cross connect in two
different ways depending on the system application. The number of DSX-1 cross
connect positions per access module is dependent upon the particular access card.
Applications in which access modules will be fed strictly from a high-speed MUX in
the shelf may not require DSX-1 wiring. Use Table 1 to determine how many DSX-1
cross connect positions to reserve for each shelf.
®
Total Access 3000/3010 System Manual
6TAPRP401-1E
TOTAL ACCESS 3000/3010
© 2002, ADTRAN, Inc.
PREP-401
Page 3 of 10