ABB Arc Guard System TVOC-2 Installation And Maintenance Manual page 7

ABB ARC GUARD SYSTEM™ – T VOC-2 INSTALL ATION AND MAINTENANCE GUIDE
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1 About Arc Guard System™
Arc Guard System™ TVOC-2 quickly detects an arc and
trips the incoming circuit-breaker. Using light as the main
condition, Arc Guard System™ trips instantaneously.
Thanks to this key functional advantage, it overrides
all other protections and delays, which is crucial when
reaction times need to be measured in milliseconds.
The Arc Guard System™ consists of the Arc Monitor and
optical sensor used for detection of the arc. For some
special applications, an additional current sensing unit
can be added. This a measure to prevent unintentional
tripping from strong light, for example, the sun.
The basic function acts in three phases:
Detection is light passing through an optical sensor.
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• Recognition is the Arc Monitor determining the
intensity of light.
• Action is the trip contact closing.
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