| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 4 Basic information (physics) 4.1 Discharge phenomena 4.1.1 General 4.1.2 Homogeneous electric fields <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4.1.3 Inhomogeneous electric fields Figures Figure 1 \u2013 Temperature dependent variation of the breakdown field strength \u00cad of air per Equation (1), \u03b1 = 0,8, \u03b8 = 20 \u00b0C, p = p0 = 1 013 mbar <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | Figure 2 \u2013 Inception voltage Ui,RMS depending on the electrode radius r, R \u226b r Tables Table 1 \u2013 Relationship between electrode radius r and corona inception voltage Ui,RMS <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | Figure 3 \u2013 Maximum electrical field strength \u00ca depending on the electrode edge radius r Figure 4 \u2013 Paschen curve \u00cad = f (p \u00d7 d) for air <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4.2 Dimensioning examples 4.2.1 General <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | Figure 5 \u2013 Principle terminal \/ contact arrangement of a 3-pole device,capacitive voltage divider <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 4.2.2 Influence of design and temperature on a series connection of clearances and solid insulation for AC voltage <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | Figure 6 \u2013 Field strength in the air gap, inhomogeneous, \u03b7 = 0,5 , \u03b5r2 = 4, cold state Figure 7 \u2013 Field strength in the solid insulation, inhomogeneous, \u03b7 = 0,5, \u03b5r2 = 4, cold state <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | Figure 8 \u2013 Field strength in the air gap, inhomogeneous, \u019e = 0,5, \u03b5r2 = 12at 130 \u00b0C operational temperature Figure 9 \u2013 Field strength in the solid insulation, inhomogeneous,\u019e = 0,5, \u03b5r2 = 12 operational temperature <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | Figure 10 \u2013 Gaps and voids in a solid andcombined solid \/ gaseous insulation [7] <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | Table 2 \u2013 Ranking of the internal field strength of different gap and void shapes [7] <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | Figure 11 \u2013 Model of a void of thickness t in an insulation wallof defined thickness d [20] <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 4.2.3 Series connection of clearances and solid insulation by design for DC voltage 4.2.4 Solid insulation \u2013 dimensioning \u2013 material characteristics Figure 12 \u2013 Principle arrangement of electrodes and insulation wallsof a 3-pole device <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | Figure 13 \u2013 Permissible field strength for dimensioning ofsolid insulation according to Equation (18) <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | Figure 14 \u2013 Breakdown at high frequency, solid insulation; d = 0,75 mm [23] <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Figure 15 \u2013 Breakdown at high frequency, solid insulation, influence of humidity; conditioning at 50 \u00b0C; 1: mica-filled phenolic, d = 0,75 mm;2: glass-silicone laminate, d = 1,5 mm [24] <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | Figure 16 \u2013 Dielectric strength \u00cad of different types of thermoplasticinsulation material depending on the temperature <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 5 Application rules 5.1 General Figure 17 \u2013 Dielectric strength Ed,RMS of PA6-GF30 in dry and moist condition (equilibrium moisture content at 23 \u00b0C\/50 % RH) depending on the temperature \u03b8 (\u00b0C) <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 5.2 Partial discharge considerations 5.3 Measures to prevent\/reduce the probability of partial discharges <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Annex A (informative)Research on partial discharge in low-voltage switchgear and controlgear A.1 General A.2 Investigations on switchgear Figure A.1 \u2013 Example of phase resolved partial discharge measurement on a MPSD atroom temperature and at elevated operational temperatures <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Figure A.2 \u2013 PD Testing (690 V, basic insulation, 20\u00b0C) Table A.1 \u2013 Inception Ui and extinction Ue voltage depending onthe temperature as per Figure A.1 and Figure A.2 Table A.2 \u2013 Maximum discharge values and number of events observed atthe test voltage as per Figure A.1 and Figure A.2 <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Figure A.3 \u2013 Inception (Ui) and extinction (Ue) voltage during partial discharge measurements on motor protection switching devices (MPSD)at elevated temperatures <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Table A.3 \u2013 Ratings and design parameters of the investigatedmotor protection switching devices (MPSD) <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | A.3 Reference to other products relevant for applications Table A.4 \u2013 Partial Discharge (PD) acceptance levels in different IEC documents <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Annex B (informative)Voltage factors when considering partial discharge effects <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | Table B.1 \u2013 Coordination of rated RMS voltage with partialdischarge voltage and extinction voltage <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Low voltage switchgear and controlgear. Partial discharge voltages and PD-level in low voltage switchgear and controlgear<\/b><\/p>\n |