OVERHEAD LINES - CALCULATION OF THE ELECTRICAL COMPONENT OF DISTANCE BETWEEN LIVE PARTS AND OBSTACLES - METHOD OF CALCULATION
International Electrotechnical Committee
FOREWORD<br>INTRODUCTION<br>1 Scope<br>2 Normative references<br>3 Terms, definitions and symbols<br> 3.1 Definitions<br> 3.2 Symbols<br>4 Approach used to derive the electrical distance<br>5 Overvoltages<br> 5.1 Classification of overvoltages<br> 5.2 Temporary overvoltages<br> 5.3 Slow-front overvoltages<br> 5.4 Fast-front overvoltages<br>6 Required withstand voltage of the air gap<br> 6.1 General<br> 6.2 Calculation of the required withstand voltage<br>7 Calculation of the distance associated with the <br> overvoltages<br>Annex A (informative) Relationship between U(50) and the <br> gap length, d<br>Annex B (informative) Example of the calculation of the <br> electrical component<br>Bibliography
Gives guidance for the calculation of electrical distances between live and earthed parts required to prevent air-gap breakdown which may endanger members of the public who legitimately come close to live parts. Applies only to overhead lines designed to operate at more than 45 kV phase-to-phase a.c. It manages the electrical component of distances between conductors and movable objects - vehicles on the ground, vessels on water, persons on top of objects or on the ground, wildlife on the ground (but not airborne), etc.
| Document Type | Standard |
| Status | Current |
| Publisher | International Electrotechnical Committee |
| Committee | TC 11 |
