Installing and wiring telephones and trunks
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. Connected multi-pair protector units (female 25-pair connector) are recommended. Table 15: Analog line circuit protectors shows the recommended protectors.
Table 15: Analog line circuit protectors
Primary* | Primary | Sneak current |
| (with heat coil) | protectors* |
| | |
3B1A (carbon) | 4B1C (carbon) | 220029 Fuse |
| | |
3B1E-W | 4B1E-W | SCP-1 |
(wide gap gas tube) | (wide gap gas tube) | |
3C1S | 4C1S | |
(solid state) | (solid state) | |
*. The 3-type protectors should be used only 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.
For catalogs and ordering information, go to the Avaya Cable Management Systems for Service Providers Web site (http://connectivity.avaya.com/exchangemax/) and click Products & Solutions.
Telephone restrictions for exposed environments
Analog telephones connected to TN746B Analog Line circuit packs cannot be installed in an exposed environment.
Digital Out-of-Building Telephone Protection
Digital out-of-building telephones require protection at both building entrances. The 4C3S-75 Enhanced Protector and the ITW Linx Enhanced Protector can be used to protect digital telephones and digital line circuit packs. These units provide primary and sneak current protection. The 4C3S-75 is equipped with a heat coil for sneak current protection, and the ITW Linx is equipped with replaceable fuses for sneak current protection.
Note:
The TN2181 16-port, 2-wire digital line circuit pack may not be approved for some out-of-building uses. Contact your Avaya representative for more information.
94 Installing and Connecting the MDF and Telephones
