GB.1 General This NNA is only applicable to all new overhead lines above A.C. 1kV. This Euronorm is only applicable to new overhead lines and shall not be applied to maintenance, reconductoring, tee-offs, extensions or diversions to existing overhead lines unless specifically required by the Project Specification. For details of the application of this standard for overhead lines constructed with covered conductor refer to the Project Specification. For details of the application of this standard to telecommunication systems involving optical fibres either incorporated in or wrapped around earthwires or conductors or suspended from overhead line supports, reference should be made to the Project Specification.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 1 SCOPE 1.1 General 2 NORMATIVE REFERENCES, DEFINITIONS AND SYMBOLS 2.1 Normative references <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 2.3 Symbols 3 BASIS OF DESIGN 3.2 Requirements of overhead lines 3.2.2 Reliability requirements 3.2.5 Strength coordination 3.2.6 Additional considerations 3.3 Limit states 3.3.3 Serviceability limit states <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 4 ACTIONS ON LINES 4.1 Introduction 4.3 Wind loads 4.3.1 Field of application and basic wind velocity <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4.3.2 Mean wind velocity 4.3.3 Mean wind pressure 4.4 Wind forces on overhead line components <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4.4.1 Wind forces on conductors 4.4.1.1 General 4.4.1.3 Drag Factor <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 4.4.3 Wind forces on lattice towers 4.4.3.1 General 4.5 Ice loads <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4.6 Combined Wind and Ice loads <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4.7 Temperature effects 4.8 Security loads <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 4.9 Safety loads 4.9.1 Construction and maintenance loads 4.9.2 Loads related to the weight of linesmen 4.10 Forces due to short-circuit currents 4.11 Other special forces <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 4.12 Load cases 4.12.2 Standard load cases <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 4.13 Partial factors for actions <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 5 ELECTRICAL REQUIREMENTS 5.2 Currents 5.2.1 Normal current 5.2.2 Short circuit current <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 5.5 Minimum air clearance distances to avoid flashover 5.5.3 Empirical method based on European experience 5.6 Load cases for calculation of clearances 5.6.1 Load cases for calculation of clearances 5.6.3 Wind load for determination of electric clearances 5.6.4 Ice load 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 <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 5.9 External clearances 5.9.1 General 5.9.4 External clearances to crossing traffic routes <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 5.9.6 External clearances to other power lines or overhead telecommunication lines 5.9.7 External clearances to recreational areas (playgrounds, sports areas, etc.) 5.10 Corona effect 5.10.2 Audible noise 5.10.2.3 Noise limits 5.10.3 Corona loss 5.11 Electrical and magnetic field 5.11.1 Electrical and magnetic fields under a line 6 EARTHING SYSTEMS 6.2 Ratings with regard to corrosion and mechanical strength 6.2.1 Earth electrodes 6.4 Dimensioning with regard to human safety <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 7 SUPPORTS 7.3 Lattice steel towers 7.3.6 Ultimate limit states 7.4 Steel poles 7.4.5 Structural analysis 7.4.6 Ultimate limit states <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 7.5 Wood Poles 7.5.1 General 7.5.5 Ultimate limit states <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 7.7 Guyed structures 8. FOUNDATIONS 8.2 Basis of geotechnical design 8.2.2 Geotechnical design 8.2.3 Design by prescriptive measures 8.2.4 Load tests and tests on experimental models 8.4 Supervision of construction, monitoring and maintenance <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 9. CONDUCTOR AND EARTH WIRES 10. INSULATORS 10.10 Characteristics and dimensions of insulators <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 11 LINE EQUIPMENT \u2013 OVERHEAD LINE FITTINGS 11.9 Characteristics and dimensions of insulator fittings 12 QUALITY ASSURANCE, CHECKS AND TAKING-OVER Annex J Angles in lattice steel towers J.4 Buckling resistance of angles in compression (see 7.3.6.4) J.4.2 Effective non-dimensional slenderness for flexural buckling J.4.3 Slenderness of members J.4.3.3 Primary bracing patterns <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | J.5 Design resistance of bolted connections (see 7.3.8) J.5.1 General <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Figure NA.1 \u2014 10-Minute mean wind speeds for GB, vb, map in metres per second <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Figure NA.2 \u2014 Ice thickness for GB, ro and (rw) in millimetres <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Figure NA.3 \u2014 Weather Zones for site heights of 0 to 100m <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Figure NA.4 \u2014 Weather Zones for site heights of 100 to 200m <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | Figure NA.5 \u2014 Weather Zones for site heights of 200 to 300m <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Figure NA.6 \u2014 Weather Zones for site heights of 300 to 400m <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | Figure NA.7 \u2014 Weather Zones for site heights of 400 to 500m <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Overhead electrical lines exceeding AC 1 kV – National Normative Aspects (NNA) for Great Britain and Northern Ireland (based on EN 50341-1:2012)<\/b><\/p>\n |