Sidactor Protection Thyristor Products Page 55 SIDACtor Protection Thyristor Products

SIDACtor Protection Thyristors 2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 02/23/17 The "Construction" section covers the following requirements: General Product Assembly Enclosures Internal Material Accessibility and Electric Shock Protection Against Corrosion Cords Current-carrying Parts Internal Wiring Interconnecting Cords and Cables Insulating Material Printed Wiring Spacing The "Risk of Injury" section covers the following requirements: Modular Jacks Sharp Edges Stability Protection of Service Personnel The "Performance" section covers the following requirements: General Impulse Voltage Measurement Overvoltage Test Endurance Conditioning Component Temperature Test Drop Test Crush Test Leakage Current Test Dielectric Voltage-withstand Test Rain Test Maximum Moment Measurement Test Weather-o-meter and Micro Tensile Strength Test Thermal Aging and Flame Test Electric Shock Current Test Manufacturing and Production Line Test Marking, Installation, and Instructions UL 497A Construction, Risk of Injury, and Performance Requirements UL 497A addresses secondary protectors for use in single or multiple pair-type communication circuits intended to be installed in accordance with Article 800 of the National Electric Code (NEC) and to have an operating voltage of less than 150 V rms with respect to Ground. The purpose of UL 497A is to help reduce the risk of fire, electric shock, or injury resulting from the deployment and use of these protectors. UL 497A requirements do not cover telephone equipment or key systems. The following key performance tests relate to overvoltage protection of the secondary protectors: 1. Impulse Voltage Measurement Test -Secondary protectors must break down within 25% of the manufacturer's breakdown rating when tested in each polarity with a rate of voltage rise of 100 V/s, 10%. Note that the manufacturer may assign separate breakdown voltage ratings for the Breakdown Voltage Measurement Test. This requirement only applies to secondary protectors that connect between Tip and Ring of the telephone loop. 2. Breakdown Voltage Measurement Test -Secondary protectors must break down within 25% of the manufacturer's breakdown rating when tested in each polarity with a rate of voltage rise no greater than 2000 V/s. The secondary protector is to be mounted in accordance with the manufacturer's installation instructions and then subjected to the test circuit shown in Figure 3.15. This requirement applies only to secondary protectors connected between Tip and Ring or Tip/Ring and Ground of the telephone loop. 3. Overvoltage Test -Secondary protectors must limit current and extinguish or open the telephone loop without loss of its overvoltage protector, indication of fire risk, or electric shock. Upon completion of this test, samples must comply with the Dielectric Voltage- withstand Test. The overvoltage test is used to determine the effects on secondary protectors and is shown in Table 3.48. Test connections are shown in Figure 3.16. Performance Tests Regulatory Requirements (continued)

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