AT&T 518-600-016 manual Static Discharge Problems

IROB PROTECTORS Equipment that is connected to the analog station jacks (408/008) and is located in a building outside of the main (control unit location) building, but within 1000 feet of the control unit is called In-Range, Out-of-Building (IROB) equipment. To protect both the control unit and the IROB equipment from exposure to lightning, inadvertent contact with power lines, and power currents induced by nearby power lines, IROB Protectors are required. Two TII Model M343 IROB protectors are required for every analog station jack that is connected to IROB equipment. The IROB protectors must be located at the cable entrance/exit of both buildings. See “IROB Protectors” on page 2-126 for more information.

TIE LINE PROTECTION

Local tie lines that extend out-of-building must have primary protection in the form of voltage limiters (typically carbon blocks or gas tubes). A protector should be provided in each building where the wiring run leaves or enters.

STATIC DISCHARGE PROBLEMS

RADIO-FREQUENCY INTERFERENCE

The MERLIN II system contains components that can be damaged by electrostatic discharge. To prevent static discharge, take these precautions:

1 Properly ground yourself when replacing modules or performing other tasks on the control unit.

2 Have the customer maintain relative humidity between

20 and 80 percent.

3 Have the customer install an antistatic mat at each voice terminal.

In most cases, radio-frequency interference (RFI), or electrical noise, is introduced to the system through trunk or voice terminal cables. However, electromagnetic fields near the control unit may also cause RFI in the system. Therefore, the control unit and cable runs should not be

System Grounding Requirements 2-9