ABB CSU-2LV, Installation And Maintenance Manual, Page: 7 / 84

ABB
ARC GUARD SYSTEM™ – CSU-2LV/2MV INSTALLATION AND MAINTENANCE GUIDE 7
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1 About Arc Guard System™
Arc Guard System™ 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 TVOC-2,
optical sensor and Current Sensing Unit CSU-2. Optical
sensors used for detection of the arc and optional current
sensing unit for detection of over current.
One or more current sensing units CSU-2 can be added to
the system as 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.
•
Recognition
is the Arc Monitor determining the
intensity of light and optionally Current Sensing Unit
determining over current.
•
Action
is the trip contact closing.