Installing A Timing Cable Ds1 Wire-Wrap Nthw75 - Nortel Passport 15000 Hardware Installation And Maintenance

554 Chapter 17 Hardware procedures

Installing a timing cable DS1 wire-wrap NTHW75

Prerequisites
Procedure steps
241-1501-240 5.2S2
Install a wire-wrap timing cable assembly to use with a DS1 alarm/BITS
module when required to comply with GR-1244 and where an external 8-kHz
BITS timing source signal is used.
• You must be familiar with "Safety considerations and best practices"
(page 53).
• The module and cable assembly are typically factory-installed. In case of
a retrofit, the cable assembly and termination block are also available in
the kit NTHW74.
• You need a timing cable assembly with PEC NTHW75. This optional
external sync cable assembly is a 2-pair tightly twisted wire-wrap cable
connecting J3 and J4 on the alarm/BITS module to an externally
mounted termination block. See the figure "A timing cable assembly
NTHW75" (page 557).
• The external sync wire-wrap cable assembly NTHW75 can only be used
with the DS1 alarm/BITS module NTHW76 for Passport 15000 or
NTPN78 for Passport 20000.
• You need a driver for the 10-mm (3/8-in.) hex screws that has at least a
10-cm (4-in.) reach to get past the terminal block.
• For custom-made cables, see cable specifications in the 241-1501-200
Passport 15000, 20000 Hardware Description.
1 Use 2 thread-forming 10-mm (3/8-in.) hex-head screws to fasten the wire-
wrap terminal block to the rear of the NEBS 2000 frame uprights within
63.5 cm (25 in.) of the alarm/BITS module. The mounting ears are shown
in the figure ""A timing cable assembly NTHW75" (page 557)".
2 Run the cable assembly down the side of the NEBS 2000 frame until the
alarm/BITS module is within reach.
3 Use tie-wraps to loosely dress the cables to the side of the frame.
4 Run the customer-supplied BITS cables from the site timing source to the
terminal block of the NTHW75.