Telecommunications Industry Association

Telecommunications User Premises Equipment Surge Resistibility of Smart Grid Equipment Connected to either DC or 120/240 V Single Phase AC and Metallic Communication Lines
 N TIA-1194

Annotation

This Standard applies to premises equipment that is connected to one or more metallic conductive communication line(s) and either a DC power source, or a 120/240 V single phase AC power service with the neutral grounded at the service entrance. It specifies the test procedures and resistibility requirements under which the communications ports of the equipment shall continue to demonstrate basic functionality when subjected to overvoltages and overcurrents on either the power lines or the communications line(s). Overvoltages or overcurrents covered by this Standard include surges due to lightning on or near the power lines or telecommunications line(s). This Standard covers the case where two or more services connected to the equipment have ground connections that may be separated by significant impedance.

PURPOSE

Most standards for the resistibility of equipment to electrical surges assume that a zero (or very low) impedance exists among all the grounds in the equipment, or among the connections to separate earth grounds. For equipment installed in the smart grid (or indeed, anywhere), the impedance of the ground connections may be significant. The purpose of this standard is to provide tests and performance criteria for the resistibility to lightning strikes of equipment connected to two or more services having at least one ground connection separated from the others by a significant impedance.

Examples of equipment with services having separate grounds include a smart grid power meter that is connected to the AC power at one side of a building and a communications service at the opposite side or a roof-mounted photovoltaic system with a communications link to the smart grid (see Figure 1).