Sidactor Protection Thyristor Products Page 41 SIDACtor Protection Thyristor Products

SIDACtor Protection Thyristors 2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 02/23/17 Although the International Telecommunication Union (ITU) does not have the authority to legislate that organizations follow their recommendations, their standards are recognized throughout Europe and the Far East. ITU-T, the Telecommunication Standardization Sector of the ITU, developed fundamental testing methods that cover various environmental conditions to help predict the survivability of network and customer-based switching equipment. The testing methods cover the following conditions: Surges due to lightning strikes on or near twisted pair and plant equipment (excluding a direct strike) Short-term induction of AC voltage from adjacent power lines or railway systems Direct contact between telecommunication lines and power lines (often referred to as AC power fault) Two ITU-T standards apply for most telecommunications equipment connected to the network: ITU-T K.20 ITU-T K.21 ITU-T K.20 is primarily for switching equipment powered by the central office; however, for complex subscriber equipment, test administrators may choose either K.20 or K.21, depending on which is deemed most appropriate. Note : Both specifications are intended to address equipment reliability versus equipment safety. For specific concerns regarding equipment safety, research and follow national standards for each country in which the equipment is intended for use. K.21 covers telecommunication equipment installed at customer premises. Equipment submitted under these requirements must meet one of two levels: basic or enhanced. Guidelines for determining under which level the equipment under test (EUT) falls can be found in ITU-T K.11, but note that the final authority rests with the test administrator. ITU-T K.44 describes the test conditions used in K.20 and K.21. ITU-T defines the following acceptance criteria: Criterion A states that equipment shall withstand the test without damage and shall operate properly after the test. It is not required to operate correctly during the test. Criterion B states that a fire hazard shall not occur as a result of the tests. Any damage shall be confined to a small part of the equipment. Table 3.25 shows the lightning surge test conditions for ITU K.20. Figure 3.5 shows the connection schematic for the lightning surge tests. Table 3.26 shows the power fault test conditions for ITU K.20. Figure 3.6 shows the connection schematic for the power fault tests. Table 3.27 and Table 3.28 show the same test conditions respectively for ITU K.21. Table 3.25 K.20 Lightning Test Conditions for Telecom Equipment in Central Office/Remote Terminal Voltage (10x700 s) Current (5x310 s) Basic/Enhanced (A) Repetitions * Primary Protection Acceptance Criteria Single Port Metallic and Longitudinal Basic/Enhanced Multiple Ports Longitudinal Only Basic/Enhanced 1 kV/1.5 kV 25/37.5 5 None ** A 4 kV/4 kV 100/100 5 Installed if used A 1.5 kV/1.5 kV 37.5/37.5 5 None A 4 kV/6 kV 100/150 5 Installed if used A * One-minute rest between repetitions ** Test not conducted if primary protection is used Table 3.26 K.20 Power Fault Test Conditions for Telecom Type Ports, Metallic, and Longitudinal Voltage Basic/Enhanced Current Basic/Enhanced (A) Duration Basic/Enhanced Repetitions * Primary Protection Acceptance Criteria Basic/Enhanced 600 V/600 V 50 Hz or 60 Hz 1/1 0.2 s 5 None A/A 600/1.5 kV 50 Hz or 60 Hz 1/7.5 1 s/2 s 5 None A/A 230/230 V -- 50 Hz or 60 Hz 23/23 15 min 1 None B/B 11.5/11.5 B/B 5.75/5.75 B/B 2.875/2.875 B/B 1.44/1.44 B/A 0.77/0.77 B/A 0.38/0.38 B/A 0.23/0.23 B/B * One-minute rest between repetitions Regulatory Requirements (continued)

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