General (snc) EE.1 Application to new lines In Estonia the standard EN 50341-1 (Part 1) can only be applied using this NNA (EN 50341-2-20) containing National Normative Aspects for Estonia. This Part 2-20 applies to all new overhead electric lines with nominal system voltages exceeding AC 1 kV and also for low voltage (below 1 kV AC) overhead lines performed by aerial cables. The requirements of the structural design are applicable also for DC overhead lines, where the electrical requirements are given in the Project Specification. (ncpt) EE.2 \u201c New overhead line\u201d A \u201cnew overhead line\u201d means a completely new line between two points, A and B. A new branch line of the existing power line should be considered as a new power line including the junction support. Specific requirements for junction support should be defined with the Project Specification. 1.2 Field of application (ncpt) EE.1 Application to covered conductors and aerial cables The standard includes requirements for the design and construction of overhead lines with nominal system voltages up to 45 kV AC equipped with covered conductors and aerial cables. Additionally, the requirements of the equipment standards and manufacturers\u2019 instructions shall be followed. (A-dev) EE.2 Application to mounting of telecommunication equipment The Standard EVS-EN 50341:2013 is applicable to fixing of structural elements for tele-communication (antennas, All Dielectric Self Supporting (ADSS) equipment, junction boxes, etc.), if mounted on power line supports (towers), especially regarding wind forces and ice loads on such fixed elements. The design and installation should be done under the due control of the line owner and\/or the competent authority. Mounting of telecommunication equipment on power line supports must be coordinated with the line owner and stated in the Project Specification. This standard applies to telecommunication lines only in the case of their common installation with power lines. This standard does not apply to separately installed telecommunication overhead lines. If telecommunication equipment (antennas, dishes, etc.) will be installed in the transmission line supports, and their size, location or mounting may have major effects on the loads or design of the structures, the requirements of EVS-EN 1993-3-1\/NA:2009 shall also to be taken into account. If such structures include conductive parts, the requirements on clearances in subclause 5.8 should be applied. (ncpt) EE.3 Application to installation of other equipment Only equipment belonging to the line (electric or telecommunication line) can be installed on the overhead lines. However, with the permission of the owner of the line, equipment serving communal services or environmental protection like road signs, warning signs or warning balls, etc., may also be installed. The installation height of equipment meant to be installed and maintained by an instructed person shall be such that the work can be done without climbing the support and the distances of safe electrical work can be followed. The additional loads due to this equipment on the line supports shall be taken into account if necessary.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | European foreword <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 0 INTRODUCTION 0.7 Language 1 SCOPE 1.1 General 1.2 Field of application <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 2 NORMATIVE REFERENCES, DEFINITIONS AND SYMBOLS 2.1 Normative references <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 3 BASIS OF DESIGN 3.2 Requirements of overhead lines 3.2.2 Reliability requirements <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 3.2.3 Security requirements 3.2.5 Strength coordination 3.2.6 Additional considerations 3.3 Limit states 3.3.3 Serviceability limit states 3.4 Actions 3.4.2 Classification of actions by their variation in time <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4 ACTIONS ON LINES 4.1 Introduction 4.3 Wind loads 4.3.1 Field of application and basic wind velocity 4.3.2 Mean wind velocity 4.3.3 Mean wind pressure 4.3.5 Wind forces on any overhead line component <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4.4 Wind forces on overhead line components 4.4.1 Wind forces on conductors 4.4.1.1 General 4.4.1.2 Structural factor 4.4.1.3 Drag factor 4.4.2 Wind forces on insulator sets <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 4.4.3 Wind forces on lattice towers 4.4.3.1 General 4.4.4 Wind forces on poles 4.5 Ice loads 4.5.1 General 4.5.2 Ice forces on conductors 4.6 Combined wind and ice loads 4.6.1 Combined probabilities <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 4.6.2 Drag factors and ice densities 4.7 Temperature effects 4.8 Security loads 4.8.4 Mechanical conditions of application 4.9 Safety Loads 4.9.1 Construction and maintenance loads <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 4.9.2 Loads related to the weight of linesmen 4.10 Forces due to short-circuit currents 4.11 Other special forces 4.11.1 Avalanches, creeping snow 4.11.2 Earthquakes 4.11.3 Floating of ice, accidents of vessels <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 4.11.4 Mining out areas 4.12 Load cases 4.12.1 General 4.12.2 Standard load cases <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 4.13 Partial factors for actions <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 5 ELECTRICAL REQUIREMENTS 5.1 Introduction 5.2 Currents 5.2.1 Nominal current 5.2.2 Short-circuit currents 5.3 Insulation co-ordination 5.4 Classification of voltages and overvoltages 5.4.1 General <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 5.5 Minimum air clearance distances to avoid flashover 5.5.1 General <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 5.6 Load cases for calculation of clearances 5.6.2 Maximum conductor temperature 5.6.3 Wind loads for determination of electric clearances 5.6.3.1 Wind load cases <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 5.6.4 Ice loads for determination of electric clearances 5.6.5 Combined wind and ice loads 5.8 Internal clearances within the span and at the top of support 5.9 External clearances 5.9.1 General <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 5.9.2 External clearances to ground in areas remote from buildings, roads, etc. 5.9.3 External clearances to residential and other buildings <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 5.9.5 External clearances to adjacent traffic routes 5.9.6 External clearances to other power lines or overhead telecommunication lines <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 5.9.7 External clearances to recreational areas (playgrounds, sports areas, etc.) <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | 5.9.8 External clearances to line crossing pipelines or adjacent pipelines, including gas and oil pipelines <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 5.9.9 Overhead lines adjacent to aerodromes <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 5.10 Corona effect 5.10.2 Audible noise 5.10.2.3 Noise limit 5.10.3 Corona loss 6 EARTHING SYSTEMS 6.1 Introduction 6.1.3 Earthing measures against lightning effects 6.2 Ratings with regard to corrosion and mechanical strength 6.2.1 Earth electrodes <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 6.2.2 Earthing and bonding conductors 6.4 Dimensioning with regard to human safety 6.4.1 Permissible values for touch voltages 6.4.3 Basic design of earthing systems with regard to permissible touch voltage <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | 7 SUPPORTS 7.1 Initial design considerations 7.1.1 Introduction 7.2 Materials 7.2.6 Wood 7.3 Lattice steel towers 7.3.1 General 7.3.6 Ultimate limit states 7.3.6.1 General 7.3.6.4 Buckling resistance of members in compression <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 7.3.8 Resistance of connections 7.4 Steel poles 7.4.8 Resistance of connections 7.4.8.2 Bolts (other than holding-down bolts) 7.4.8.3 Slip joint connections 7.5 Wood poles 7.5.3 Materials 7.5.5 Ultimate limit states 7.5.5.3 Resistance of wood elements 7.5.5.4 Decay conditions 7.10 Maintenance facilities 7.10.1 Climbing <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 7.10.2 Maintainability 7.10.3 Safety requirements 8 FOUNDATIONS 8.1 Introduction <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | 8.2 Basis of geotechnical design 8.2.2 Geotechnical design by calculation <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 8.2.3 Design by prescriptive measures 8.2.4 Load tests and tests on experimental models 8.3 Soil investigation and geotechnical data 8.5 Fill, dewatering, ground improvement and reinforcement 8.6 Interactions between support foundations and soil <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 9 CONDUCTORS AND EARTH-WIRES 9.1 Introduction 9.2 Aluminium based conductors 9.2.1 Characteristics and dimensions <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | 9.6 General requirements 9.6.2 Partial factors for conductors 10 INSULATORS 10.2 Standard electrical requirements 10.4 Pollution performance requirements <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | 10.7 Mechanical requirements 10.10 Characteristics and dimensions of insulators <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | 11 HARDWARE 11.6 Mechanical requirements 12 QUALITY ASSURANCE, CHECKS AND TAKING OVER <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Overhead electrical lines exceeding AC 1 kV – National Normative Aspects (NNA) for ESTONIA (based on EN 50341-1:2012)<\/b><\/p>\n |