LV3.6.2 - 3.6.2 LV Solid State Surge Protective Components WG

Michael J Maytum

This standard defines the basic electrical parameters to be met by silicon PN junction voltage clamping components used for the protection of telecommunications equipment or lines from surges. It is intended that this standard be used for the harmonization of existing or future specifications issued by PN diode surge protective component manufacturers, telecommunication equipment manufacturers, administrations or network operators.

This standard sets terms, test methods, test circuits, measurement procedures and preferred result values for silicon thyristor-based surge protective components used for overvoltage or overcurrent or both protection in low-voltage information technology communications system items. The thyristor variants covered are: Unidirectional characteristic Bidirectional characteristic Two terminal (diode) fixed voltage Three or more terminal gate controlled Integrated series diode types for low capacitance.

Varistors for surge-protective applications on systems with dc to 420 Hz frequency and voltages equal to or less than 1000 V rms, or 1200 V dc, are covered. Definitions, service conditions, and a series of test criteria for determining the electrical characteristics of the varistors are provided. The tests are intended as design tests and provide a means of comparing various surge-protective devices.

A two-terminal avalanche junction surge suppressor for surge-protective application on systems with dc to 420-Hz frequency and voltages equal to or less than 1000 V rms or 1200 V dc is considered. The device is a single package that may be assembled from any combination of series and/or parallel diode chips. Definitions, service conditions, and a series of test criteria for determining its electrical characteristics are provided. These devices are used as surge diverters for limiting transient overvoltages in power and communications circuits.

This standard applies to two or three terminal, four or five layer, thyristor surge protection devices (SPDs) for application on systems with voltages equal to or less than 1000 V rms or 1200 V dc.

Applications information on fixed voltage and gated thyristor surge protective devices(SPDs) are provided. Key device parameters and their sensitivities are explained. Several workedtelecommunication circuit design examples are given.

Applications information on fixed-voltage and gated-thyristor surge protective components (SPCs) is provided. Key device parameters and their sensitivities are explained. Several worked telecommunication circuit design examples are given.

Test methods and preferred values for metal-oxide varistor (MOV) surge protective components are covered in this standard and have the following main parameter ranges: packaging (leaded disc-type or surface mount), nominal varistor voltage (5 V to 1200 V), 8/20 surge current rating (10 A to 70 kA), and 8/20 clamping voltage (10 V to 3 kV). With appropriate component selection, these components could be used for the overvoltage protection of power and signal systems having continuous ac voltages (2.5 V rms to 750 V rms), steady-state dc voltages (3.3 V to 1000 V), and peak signal feed voltages (3.5 V to 850 V). Information is given on manufacturer type testing used to determine environmental performance and rated values.

The basic requirements to be met by series connected, solid-state, self-restoring overcurrent protectors (OCPs) for the protection of telecommunication equipment and lines are presented. This standard should be used for the harmonization of existing or future specifications issued by solid-state, self-restoring OCP manufacturers, telecommunication equipment manufacturers, administrations, or network operators.

Terms, test methods, test circuits, measurement procedures, and preferred result values for the surge mitigation parameters of isolating transformers used in networking devices and equipment are set in this standard. Three types of isolating transformer are considered: mains low frequency power, high frequency power (switching mode power supplies) and signal (e.g., Ethernet data).

Avalanche breakdown diodes used for surge protection on systems with voltages equal to or less than 1000 V rms or 1200 V dc are discussed in this standard. The avalanche breakdown diode surge suppressor is a semiconductor diode that can operate in eithere the forward or reverse direction of its V-I characteristic. This component is a single package, which may be assembled from any combination of series and/or parallel diode chips. This standard contains definitions, service conditions, and a series of test criteria for determining the electrical characteristics and verifying ratings of these avalanche breakdown diodes. If the characteristics differ with the direction of conduction, then each direction of conduction shall be separately specified.