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DEFINITY Enterprise Communications Server Release 6
Installation and Test for Compact Modular Cabinets
555-230-128
Issue 3
May 1998
Install and Cable the Cabinets
Page 1-88Install Off-Premises Station Wiring
1
Digital Out-of-Building Telephones
Protection is required at both building entrances for digital out-of-building voice
terminals. There are 2 different types of protectors that can be used to protect
digital voice terminals and digital line circuit packs. The 2 protectors to use are
the 4C3S-75 Enhanced protector and the ITW Linx Enhanced Protector. These
units provide primary and sneak current protection. The 4C3S-75 is equipped
with a heat coil for sneak current protection. The ITW Linx is equipped with
replaceable fuses for sneak current protection.
The 4C3S-75 is only used with Vintage 14 or newer TN754 circuit packs. The
4C3S-75 can be used on all vintages of the TN754B circuit packs. The ITW Linx
may be used on all vintages of the TN754 circuit packs. Table 1-15
lists the
approved protectors.
NOTE:
The TN2181 (2-Wire 16 Port Digital Line circuit pack) may not be approved
for some out-of-building uses. Contact your Lucent Technologies
representative for more information.
When possible, all new and reused wiring installations should use blocks that
accept the standard 5-pin plug-in 4C3S-75 protector. However, this may not be
cost-effective in some cases. For these installations, the ITW Linx protector may
be installed. An example of this is where screw-type carbon block protectors (or
other non plug-compatible types) are in place and it is too costly to re-terminate
the outside plant cable on a 5-pin mounting block for only a few out-of-building
terminals.
The ITW Linx Enhanced Protector may be installed in series with existing primary
protection. Note the 4C3S-75 protector cannot be installed in series with other
types of primary protection. It must be installed as the only protection on the line
entering the building. For the 4C3S-75 protector, various 25-, 50-, and 100-pair
protector panels are equipped with 110-type connecting blocks and/or RJ21X
connectors. The ITW Linx Enhanced Protector mounts directly on connecting
blocks and requires a separate ground bar.
Table 1-15. Digital Voice Circuit Protectors
Circuit Pack
Enhanced Primary Protector
(With Sneak Current Protection)
TN754 V13 or earlier ITW Linx Only
TN754 V14 or later 4C3S-75 or ITW Linx
TN754B all vintages 4C3S-75 or ITW Linx
TN2181 4C3S-75 or ITW Linx
TN2224 4C3S-75 or ITW Linx