ABB CSU-2LV, Installation And Maintenance Manual, Page: 16 / 84

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ABB
ARC GUARD SYSTEM™ – CSU-2LV/2MV INSTALLATION AND MAINTENANCE GUIDE
3.2.7 Current Sensors
The current sensors are based on the principle of
the Rogowski coil. The sensors consist of an air-core
winding, immune to any risk of saturation as they have no
ferromagnetic core. The measurement is linear over the
whole measuring range. The output signal is a voltage,
which is proportional to the derivative of the current.
3.2.8 Event Logs
The event log is divided into 4 parts, “Over current”,
“Current warning”, “Error”, “Parameter change”, each
displaying info of their type.
Each event log holds the 10 last events of its type when
each individual event log is full, the oldest event will be
removed upon the arrival of a new event of that type.
The “Combined” event log will show all events sorted upon
the time of occurrence, this log shows a maximum of 4 x
10 = 40 events.
Even if the internal time of the CSU-2 has been reset
or changed, the events in all of the logs will always be
presented in correct order after the time of occurrence.
3.2.9 Backup
CSU-2 saves all parameters internally but has no built
in support for backups. To ensure that the device can
be restored to a known good state, manual backup of
parameters via display and or Modbus has to be performed
(parameters “automatic reset”, “language” and “brightness”
can not be accessed via Modbus).
3.2.10 Home button
The home button allows to:
• Navigate to home.
• Restart the setup sequence during the start-up sequence.
• Reset Current Warning. That is to say, pushing the
home button, it can help you to leave Current Warning
notification window.
• Wake up the screen during sleep mode.
3.2.11 LED descriptions
For LED descriptions see “8.3.1 LED-lights” on page 73.
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