Electrical Contacts, 2nd Edition

9

The Arc and Interruption

Paul G. Slade

All the elements of earth except Hydrogen and some Helium … were made in the interiors of collapsing stars. We are made of star stuff.

Cosmos, Carl Sagan

CONTENTS

9.1      Introduction

9.2      The Fourth State of Matter

9.3      Establishing an Arc

9.3.1      Long-Gap Gas Breakdown

9.3.2      Vacuum Breakdown and Short-Gap Breakdown

9.3.3      The Volt–Current Characteristics of Separated Contacts

9.4      The Formation of the Electric Arc

9.4.1      The Formation of the Electric Arc During Contact Closing

9.4.2      The Formation of the Electric Arc During Contact Opening

9.5      The Arc in Air at Atmospheric Pressure

9.5.1      The Arc Column

9.5.2      The Cathode Region

9.5.3      The Anode Region ...