Switch disconnectors Technology primer Protecting, switching and disconnecting with switch disconnectors and fuses
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Switch disconnectors Technology primer Protecting, switching and disconnecting with switch disconnectors and fuses

Contents Preface List oftables 1. Introduction to electrical protection 8 2.4. Basic principles of a fuse 18 2.4.2. Function, technical specifications, and characteristic curves 19 2.5. Basic device types and application examples 26 2.5.2. Switch disconnectors with fuses 28 2.5.3. Fuse switch disconnectors 30 2.5.4. Transfer switching equipment or load transfer switches 32 2.6. Basic principles of switchover 34 2.6.1. Types of transfer switches 34 2.6.2. Selection criteria for switchover 37 3. General technology comparison: Fuse versus circuit breaker 40 4. The Siemens product portfolio for...

4.2.4. DIAZED/NEOZED fuses 4.3. Fuse switch disconnectors 4.3.1.3NP fuse switch disconnectors 4.3.2. 3NJ4 fuse switch disconnectors 4.4. Switch disconnectors with fuses 4.4.1.3KF switch disconnectors with fuses 4.4.2. 3NJ6 switch disconnectors with fuses 4.5. Load transfer switches and transfer switching equipment 4.5.1. 3LD load transfer switches 4.5.2. 3KC transfer switching equipment 4.5.2.1.3KC0 manual transfer switching equipment (MTSE) 4.5.2.2. Transfer switching equipment with motor operator 4.5.2.2.1.3KC3 and 3KC4 remote transfer switching equipment (RTSE) 4.5.2.2.2. 3KC6 and 3KC8...

SENTRON Technology Primer | Preface Preface According to the requirements outlined in international standards and installation regulations (e.g. fire protection or escape stairs), electrical equipment must be effectively protected against overload and short circuits. Protection, switching, measuring, monitoring or power monitoring – Siemens low-voltage circuit protection technology offers a broad portfolio of devices and software solutions for all areas of electrical installation technology. This puts you in full control of all electric circuits – in industry as well as in non-residential...

Table of Abbreviations | SENTRON Technology Primer ATC automatic transfer control device ATSE automatic transfer switching equipment CCC China Compulsory Association DC direct current fur Normung e.V. EN European standard I electrical current intensity Commission IEV International Electrotechnical LRS Lloyd's Register of Shipping MCC motor control center MCCB molded case circuit M effect mesomeric effect MTSE manually operated transfer switching equipment N neutral conductor NEC National Electrical Code NEMA National Electrical Manufacturers Association NFPA National Fire Protection...

SENTRON Technology Primer | List of Figures List of figures Figure 1: IEC and UL markets at a glance 11 Figure 2: Selective system vs. non-selective system 14 Figure 3: Combination of characteristic curves for full selectivity 16 Figure 4: Combination of characteristic curves for partial selectivity 17 Figure 5: Structure of a fuse (example: LV HRC fuse) 19 Figure 6: Short-circuit current limiting 20 Figure 7: Characteristic curve for gG, gR and gS 23 Figure 8: Time/current characteristic 25 Figure 9: Switch disconnectors as EMERGENCY-STOP, repair or main control switch of machinery and...

List of Tables | SENTRON Technology Primer Figure 12: Transfer switches for switching over between networks or loads 33 Figure 13: Types of transfer switches 34 Figure 14: Transfer switching with switch disconnectors and circuit breakers 35 Figure 15: Exemplary structure of transfer switching considering the criticality of the loads 38 Figure 16: Schematic application structure 58 List of tables Table 1: Utilization categories for switch disconnectors and fuse technology 13 Table 3: Operational classes and applications 22 Table 4: Comparison of fused solution and circuit breaker solution 40

SENTRON Technology Primer | Introduction to Electrical Protection 1. Introduction to electrical protection When dealing with electricity, safety has top priority. According to the requirements outlined in international standards and installation regulations, every qualified electrician must effectively protect electrical equipment, in particular cables and conductors, against overload and short circuits by implementing suitable (protective) measures. Preferably, such protection is achieved with the use of suitable switching/protective devices, which will automatically disconnect defective...

Technical Basics | SENTRON Technology Primer 2. Technical basics Various factors play a decisive role in the selection of the right switching and protection device. First and foremost is the choice of a basic device from the various switch disconnectors, fuse switch disconnectors, switch disconnectors with fuses and changeover switches. In the next step, the technical data and specifications are most relevant. For better understanding, these key features are explained in more detail in the appendix. Finally, it must be ensured that the approval requirements of the respective country or area...

SENTRON Technology Primer | Technical Basics 2.1. Certification and approval The use of electrical equipment for switchgear and controlgear assemblies is regulated by the legislation of the corresponding country. The most important technical features of low-voltage fuses and switchgear are codified in the standards of the International Electrotechnical Commission (IEC) based in Geneva. Even beyond Europe, devices in accordance with the IEC standard are used in Asia, South and Central America and Australia. The European standards (EN) are generally identical to those of the IEC. In some...

Technical Basics | SENTRON Technology Primer Figure 1: IEC and UL markets at a glance

SENTRON Technology Primer | Technical Basics 2.2. Utilization categories Utilization categories are a “combination of specified requirements related to the condition in which the switching device or the fuse fulfills its purpose, selected to represent a characteristic group of practical applications” (International Electrotechnical Vocabulary – IEV 441-17-19). Utilization categories subdivide the various switching tasks (applications), whereby there are different test conditions for each category. Utilization categories provide the user with orientation in the selection of low-voltage...