Lucent Technologies definity Installation Manual page 95

DEFINITY Enterprise Communications Server Release 6
Installation and Test for Compact Modular Cabinets 555-230-128
1 Install and Cable the Cabinets
Install Off-Premises Station Wiring
Circuit Protectors
Carbon block, or equivalent protection is required at both building entrances.
Also sneak current protection is required. Protection can be provided by a 4-type
protector or a 3-type protector plus a separate sneak current protector. The
4-type protector is equipped with a heat coil.
The 4-type protector is the preferred device. For installations not using primary
protection, 4-type protectors should always be used. When the 3-type protector
is already installed, a separate sneak current protector is required. The multi-pair
protector units and the off-premises cabling must be locally engineered.
Connectorized multi-pair protector units (female 25-pair connector) are
recommended.
Table 1-14. Analog Line Circuit Protectors
1
Primary
3B1A (carbon)
3B1E-W (wide gap
gas tube)
3C1S (solid state)
1. The 3-type protectors should only be used if they are already part of the
existing protection system. A sneak current protector is always required when
a 3-type primary protector is used.
The maximum range of out-of-building analog telephones (500-, 2500-, or
7100-types) connected to an analog line circuit pack should be such that the
maximum loop resistance does not exceed 1300 Ohms.
The following voice terminals cannot be installed in an exposed environment:
7300-type voice terminals connected to TN762 Hybrid Line circuit packs
Multi-button Electronic Telephone (MET) sets connected to TN735 MET
Line circuit packs
Analog telephones connected to TN746 Analog Line circuit packs
Refer to Table 1-1 on page 1-3
(comcodes).
Table 1-14 shows the recommended protectors.
Protectors
Primary
(with heat coil)
4B1C (carbon)
4B1E-W (wide gap gas tube)
4C1S (solid state)
for circuit protector ordering information
Issue 3
May 1998
Page 1-87
Sneak Current
1
Protectors
220029 Fuse
SCP-1