Electrical Contacts, 2nd Edition

15

Arc Faults and Electrical Safety

John J. Shea

……should I escape thy flame,

Thou wilt have helped my soul from Death:

The Dark Angel, Lionel Johnson

Stay alert, you can observe anything by watching,

Yogi (Lawrence Peter) Berra

CONTENTS

15.1    Introduction

15.2    Arc Fault Circuit Interrupters (AFCIs)

15.3    Arcing Faults

15.3.1    Short-Circuit Arcing

15.3.2    Series Arcing

15.4    Glowing Connections

15.5    Arcing Fault Properties

15.5.1    Frequency

15.5.2    Electrode Materials

15.5.3    Arc Fault Current

15.5.4    Cable Impedance and Cable Length Effects

15.6    Other Types of Arcing Faults

15.7    Conclusions

References

15.1  Introduction

Arcing faults in electrical wiring can occur for a wide variety of different reasons [