This document is related to the insulation coordination in TC 34 standards and provides explanations on mathematical addition of working voltages, insulation between circuits, use of protective extra low voltage (PELV) and insulation between LV supply and control line conductors in order to cover new technologies associated with the use of LED light sources and controllable products.<\/p>\n
It describes in which way the addition of supply voltages and working voltages can be arranged for an assessment of the electrical insulation requirements (e.g. creepage distances and clearances) in a system if a first failure occurs.<\/p>\n
Furthermore the actual failure scenarios given in IEC 60598-1:2014 and IEC 60598- 1:2014\/AMD1:2017, Annex X and IEC 61347-1:2015, Clause 15 are explained in greater detail and the rationale behind the protective requirement for each situation is given (e.g. possible LV primary to ELV secondary does not lead to an overburden of the insulation in the second circuit).<\/p>\n
This document also describes the possibility to increase immunity and reliability of electronic circuits, used in combination with LEDs, with the use of PELV and the associated safety consequences for this system.<\/p>\n
The insulation between LV supply and control line conductors is also important and this document explains why this is an essential safety consideration for a complete installation system.<\/p>\n
| 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 | ||||||
| 5<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions 4 Mathematical addition of working voltages <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | Figures Figure 1 \u2013 Input\/output failure simulation Tables Table 1 \u2013 Addition of voltages <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 5 Insulation between circuits 5.1 General 5.2 Insulation requirements between active parts and accessible conductive parts <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | Table 2 \u2013 Insulation requirements between active partsand accessible conductive parts <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 5.3 Possible failure conditions Figure 2 \u2013 Examples of controlgear with different insulation systems Figure 3 \u2013 Condition A: failure between input and output circuits <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | Figure 4 \u2013 Condition B: earth failure\/equipotential bonding failure (interruptionof the connection continuity) Figure 5 \u2013 Condition C: insulation failure between output circuitsand accessible earthed metal part Figure 6 \u2013 Condition D: insulation failure between output circuit to conductive partswhich are connected together (equipotential bonding) <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 6 Circuits analysis Figure 7 \u2013 Condition E: insulation failure between output circuit and differentconductive parts not connected together (no equipotential bonding) Table 3 \u2013 Circuit analysis overview <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 7 Use of PELV 7.1 General <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 7.2 Characteristics of PELV (protective extra low voltage) circuits 7.3 Requirements for PELV circuits in addition to SELV 7.3.1 Voltage limitations <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 7.3.2 Touch current and protective conductor current Figure 8 \u2013 PELV circuit in the most adverse condition (touch voltage is the sum of UE and U2) Figure 9 \u2013 PELV circuit with a person located in an equipotential location(touch voltage is U2 only) <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 7.4 Summary of the proposed changes to IEC 60598-1 and IEC 61347-1 8 Insulation between LV supply and control line conductors <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Explanation of the mathematical addition of working voltages, insulationbetween circuits, and use of PELV, in TC 34 standards<\/b><\/p>\n |