Detail of YD/T 993-2016

Introduction of YD/T 993-2016

This standard is developed in accordance with the rules given in GB/T 1.1-2009. This standard replaces YD/T 993-2006 The Technical Requirements and Test Methods of Overvoltages and Overcurrents Resistibility for Telecommunication Terminal Equipment. In addition to a number of editorial changes, the following technical changes have been made with respect to YD/T 993-2006: ——Standard name is changed from The Technical Requirements and Test Methods of Overvoltages and Overcurrents Resistibility for Telecommunication Terminal Equipment to The Technical Requirements and Test Methods of Overvoltages and Overcurrents Resistibility for Wire Telecommunication Terminal Equipment. ——Some terms are standardized (see Chapter 3). ——Product application environment classification is added (see Chapter 4). ——Depending on the application environment for device port, the test items are integrated with technical requirements (see Chapter 5). ——Coaxial cable port test is added into the test content (see Chapter 5). ——According to ITU-T K.21, test items and technical requirements are updated (see Chapter 5). ——Relevant requirements for electrostatic discharge are deleted. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights; the issuing body of this document shall not be held responsible for identifying any or all such patent rights. This Standard was proposed by and is under the jurisdiction of China Communications Standards Association. Drafting organizations of this standard: China Academy of Information and Communications Technology, Huawei Technologies Co., Ltd., Alcatel Shanghai Bell Co., Ltd. Chief drafters of this standard: Zhang Yongchun, Liu Wei, Jiang Hao, Xia Lijiao, Dai Chuanyou, Liu Dianming, Zhang Kun, Zhang Ke. This standard was firstly issued in December 1998. For the purpose of this standard, its first revision was issued in May 2006 and this document is the second revision. The Technical Requirements and Test Methods of Overvoltages and Overcurrents Resistibility for Wire Telecommunication Terminal Equipment 1 Scope This standard specifies the technical requirements and test methods of overvoltages and overcurrents resistibility for wire telecommunication terminal equipment. This standard is applicable to test of protective performance of wire telecommunication terminal equipment, either indoor type or outdoor type, connected to the communication network and public supply network. 2 Normative References The following documents are indispensable for the application of this document. For dated references, only the dated editions apply. For undated references, the latest editions (including any amendments) apply. GB/T 17626.5-2008 Electromagetic Compatibility—Testing and Measurement Techniques—Surge(Impact) Immunity Test YD/T 1540-2014 Test Methods for Overvoltage and Overcurrent Resistance of Telecommunication Equipment 3 Terms, Definitions and Abbreviations 3.1 Terms and Definitions For the purposes of this document, the following terms and definitions apply. 3.1.1 TTE telecommunication equipment, connected at the public telecommunication network terminal, provides users with functions of sending and receiving information. 3.1.2 Overvoltages and Overcurrents the external voltage and current exceeding the normal working voltage and current of the equipment. 3.1.3 Simulation Lightning Surge impact on equipment when lightning stroke happens at or nearby the simulation line facilities. 3.1.4 Power Induction interference of power line or electrified railway system with adjacent communication line. 3.1.5 Mains Power Contact direct contact between power line and communication line. 3.1.6 Specific Energy a factor to measure the power induction energy, numerically equal to energy consumed by 1Ω resistance, i.e. a product of second power of induced current and time spent when current flows through. Specific Energy of signal generator is measured by placing the signal generator short circuited at output end. 3.1.7 Primary Protection a method for protecting the equipment with surge protection device, and preventing the overvoltage and overcurrent from entering into device port. The surge protection device shall be available easily and removed safely and be kept in equipotential bonding. 3.1.8 Inherent Protection a protection method, provided on device port, which can be achieved by intrinsic property, structure design or appropriate protective element. 3.1.9 Special Test Protector the circuit or component in place of coordination protector for protection of coordination. 3.1.10 External Ports a specific communication port for a specific equipment, which is connected directly with the metal conductor extended to building wiring. 3.1.11 Internal Ports a specific communication port of specific equipment, which is not connected directly with the metal conductor extended to building wiring but connected with cables for interconnecting unit. 3.1.12 Symmetric Pair Port the port connected to symmetric pair cable which is either shielded or not shielded and can connect one or more twisted pairs, in which, single pair port means only one symmetric pair in one port and multiple pair port means more than one symmetric pairs in one port. 3.1.13 Coaxial Cable Port the port connecting coaxial cable. 3.1.14 Surge Protective Device a protective device which can reduce overvoltage and overcurrent energy in a finite time and may be composed of one or more components, including at least one nonliner component. 3.1.15 Protection Coordination measures taken to ensure all the internal or external protective components can work together and limit the damage on the equipment or protective component arising from limited voltage, current or energy. 3.1.16 Dedicated Power Feed a method for power supply by dedicated cable off the buildings, excluding the method for providing feed and signal transmission. 3.1.17 Agreed Primary Protection a protection method, as agreed between equipment manufacturer and network operator, for protecting equipment by Surge Protective Device. 3.1.18 High Current Carrying Protection Component one of Surge Protective Device, which transfer most of overvoltage and overcurrent energy while operating and stands off the protective equipment. The protective component is mainly used for primary protection but under specified conditions, it also can be installed for inherent protection. 3.2 Abbreviations For the purpose of this document, the following abbreviations apply. CPE Customer Premises Equipment dpf Dedicated Power Feed EUT Equipment Under Test GDT Gas Discharge Tube ITU-T International Telecommunication Union - Telecommunication Standardization Sector ISDN Integrated Services Digital Network LI Line Interface LT Line Termination MOV Metal Oxide Varistor NT Network Termination 4 Product Application Environment Classification 4.1 Class I Environment In the physical facility environment, all external signal ports and power supply ports shall be configured with well-grounded primary protector at the cable entry to external ports, as shown in Figure 1. Class I environmental facilities mainly include, but are not limited to: ——Remote machine room; ——Machine room within user building and commercial buildings; ——Physical facilities of users, like outdoor joist, outdoor container and other microcomputer room environment; ——Inside of residential buildings well grounded and equipped with primary protector (except basement). Figure 1 Class I Environment 4.2 Class II Environment There is no primary protector at the external signal port and power supply port in such physical facility environment, as shown in Figure 2. Class II environment mainly includes but is not limited to: ——Passageway, control shaft, distribution room and basement in user or commercial buildings; ——Installation environment along the street; ——Installation environment on top of and at the outer end of user building; ——Installation environment of stringing; ——Residential buildings without primary protector. Figure 2 Class II Environment For Class II application environment, the grounding communication equipment shall be well grounded while being installed, but considering the possibility that there is special application unlikely to realize the grounding, the grounding wire for communication equipment in Class II environment is plotted into dotted line. Under such special circumstances, consideration shall not only be given to the protection against overvoltages and overcurrents but also the impacts of non-grounding on the personnel safety, equipment reliability and equipment function. 4.3 Identification and Description Service environment of communication equipment shall be identified and described on the equipment nameplate, external package or instruction, including detailed description on Class I and Class II environments so that the user can judge the equipment application environment classification. 5 Technical Requirements 5.1 Test Type In this standard, four test types are present: —Transverse (line - line); —External ports to ground (longitudinal test); —External ports to external ports (this test shall be made for floating ground equipment but not for grounding equipment); —Internal port to ground (longitudinal test). Horizontal test shall be made on the equipment with external symmetric pair port, external coaxial cable port, special feed port and AC power port. Test of external ports to ground shall be made on the equipment with external ports and protective grounding or internal ports. During the test, all ports not tested, regardless of internal or external ones, shall be terminated. For the ungrounded equipment with internal port, the test is made again and again when each type of internal port is grounded via couplers. Test of external ports to external ports shall be made on the equipment with more than one external port. During the test, all the ports not tested, regardless of internal or external ones, shall be terminated. Each type of external port, including that of the same type shall be grounded via couplers. Test sequence is as shown in Figure 3. Example for test sequence: (transverse test); (external ports to ground): and coupled to the ground (external ports to ground with one internal port coupled to the ground); unconnected (external ports to external ports with one external port coupled to the ground); (internal port to ground) Figure 3 Example for Test Sequence The test of internal port to ground shall be made at all types of internal ports. 5.2 Protection Coordination Test See Chapter 8 of YD/T 1540-2014 for relevant technical requirements for protection coordination test.

Contents of YD/T 993-2016

Foreword i 1 Scope 2 Normative References 3 Terms, Definitions and Abbreviations 3.1 Terms and Definitions 3.2 Abbreviations 4 Product Application Environment Classification 4.1 Class I Environment 4.2 Class II Environment 4.3 Identification and Description 5 Technical Requirements 5.1 Test Type 5.2 Protection Coordination Test 5.3 Technical Requirements 6 Test Method 6.1 Test Condition 6.2 Recommended Test Procedures 6.3 Simulation Lightning Surge Test 6.4 Power Induction 6.5 Mains Power Contact Test Annex A (Normative) Example of Test Circuit Configuration Annex B (Normative) Qualification Criteria