AF0100 Arc-Flash Relay
GENERATOR APPLICATION GUIDE
2
Littelfuse.com/ArcFlash
© 2017 Littelfuse Products
TABLE OF CONTENTS
GENERATORS
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Challenges Unique to Generators .................................................................................................................................3
NEC
®
ARTICLE 240.87 (2017)
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Background ...................................................................................................................................................................4
Documentation .............................................................................................................................................................4
Method to Reduce Clearing Time .................................................................................................................................4
ANSI Z10 : RISK CONTROL HIERARCHY
.....................................................................................................................4
Background
..................................................................................................................................................................4
Methods ........................................................................................................................................................................4
GENERATOR PROTECTION USING AF0100
................................................................................................................5
Generator To Generator Breaker Connection ................................................................................................................5
Transformer Enclosure ..................................................................................................................................................5
AF0100 CONNECTION DIAGRAM
.................................................................................................................................6
SENSOR COVERAGE
.....................................................................................................................................................7
EFFECT OF GENERATOR GROUNDING ON ARC-FLASH RISK
.................................................................................8
Ungrounded Generator .................................................................................................................................................8
Solidly Grounded Generator ..........................................................................................................................................8
Resistance-Grounded Generator ..................................................................................................................................8
ADVANTAGES OF RESISTANCE GROUNDING FOR GENERATORS
.........................................................................9
BENEFITS TO ADDING ARC-FLASH RELAYS
............................................................................................................10
WHY CHOOSE LITTELFUSE?
......................................................................................................................................10
APPENDIX A: SUPPORTING MATERIALS
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AF0100 COMMISSIONING INFORMATION
............................................................................................................... 11
