AT&T System 85 Requirements, Exposed Ports And Terminals Defined, Out-of-Building Campus Stations

EXPOSED PORT PROTECTION

EXPOSED PORT PROTECTION

Requirements

All port packs and terminals require unique protection and grounding arrangements as defined in the checklists (AT&T System 75 Electrical Protection, Grounding, and Exposure Checklist, 555-200-120 and AT&T System 85 Electrical Protection, Grounding, and Exposure Checklist, 555-103-120). These arrangements provide an adequate barrier to the potentially damaging vol- tages and currents inherent in lightning and power surges present in exposed applications. Moreover, the National Electrical Code requires that an approved protector be provided on all exposed circuits.

Exposed Ports And Terminals Defined

Ports and terminals that utilize facilities that are subject to disturbances from lightning, ground potential rises (GPR), or possible contact or induction from electrical power sources or circuits in excess of 300 volts (RMS) to ground are classified as exposed. Any ports or terminals served by such exposed facilities are classified as exposed and require protection at both the port and ter- minal ends. The checklists contain flowcharts that are beneficial in determining exposure status and tables to determine the type of protector required.

Out-of-Building Campus Stations

An out-of-building campus station is a telephone or voice terminal that is not physically located in the same building as the equipment room, but is located on the same property. Both analog tele- phones and digital voice terminals can be used as out-of-building stations

Carbon block, or equivalent, protection is required at both building entrances for analog out-of- building stations. Sneak current protection is also required. Protection can be provided by a

4-type protector or a 3-type protector plus a separate sneak current protector. The 4-type protec- tor is equipped with a heat coil for sneak current protection. The 4-type primary protector is the preferred device.

Protection is required at both entrances for digital out-of-building voice terminals. There are two different types of protectors that can be used to protect digital voice terminals and digital line cir- cuit packs in an out-of-building environment: the 4C3S-75 Enhanced Protector and the ITW Linx Enhanced Protector.

Note: The 4C3S-75 Enhanced Protector may only be used on Vintage 14 or newer TN754 Circuit Packs. The 4C3S-75 can be used on all vintages of the TN754B Circuit Pack. The ITW Linx Enhanced Protector may be used on all Vintages of the TN754 and TN754B Circuit Packs.

The 4C3S-75 Enhanced Protector is equipped with a heat coil for sneak current protection and the ITW Linx Enhanced Protector is equipped with replaceable fuses for sneak current protection.

The maximum range for out-of-building voice terminals is 3,400 feet when using 24 AWG wire

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