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Event block name
Event names
COL2
Block ON
COL2
Block OFF
The function registers its operation into the last twelve (12) time-stamped registers; this information is
available for all provided instances separately. The register of the function records the ON event
process data for START, TRIP or BLOCKED. The table below presents the structure of the function's
register content.
Table. 5.3.2.1 - 53. Register content.
Date and time Event
Fault type
Pre-trigger
current
Fault
current
Pre-fault
current
Trip time
remaining
Used SG
dd.mm.yyyy
hh:mm:ss.mss
Event
name
L1-E…L1-L2-L3 Start/trip -20
ms current
Start/Trip
current
Start -200
ms current
0…1800 s
Setting group
1...8 active
5.3.2.2 Capacitor bank neutral unbalance protection (Cnu>; 50UB)
The capacitor bank neutral unbalance function uses a total of eight (8) separate setting groups which
can be selected from one common source.
Function operation is activated by a settable definite time delay, which is counted from the moment
when the alarm or trip threshold is exceeded. The basic design of the protection function is the three-
pole operation.
The operational logic consists of the following:
• unbalance measurement input selection
• unbalance measurement input selection
• input magnitude processing
• threshold comparator
• block signal check
• time delay characteristics
• output processing.
The inputs for the function are the following:
• operating mode selections
• setting parameters
• digital inputs and logic signals
• measured and pre-processed current magnitudes.
The function's outputs are ALARM START, ALARM, START, TRIP and BLOCKED signals which can be
used for direct I/O controlling and user logic programming. The function generates general time-
stamped ON/OFF events to the common event buffer from each of the output signals. In the instant
operating mode the function outputs START and TRIP events simultaneously with an equivalent time
stamp. The time stamp resolution is 1 ms. The function also provides a resettable cumulative counter
for the ALARM START, ALARM, START, TRIP and BLOCKED events.
The following figure presents a simplified function block diagram of the capacitor bank neutral
unbalance function.
A
AQ
Q-C255
-C255
Instruction manual
Version: 2.06
© Arcteq Relays Ltd
IM00035
69