The programmable operating curve allows the user to freely program the timing behaviour of the
protection stage with current or time points, either with step or two-point interpolated time calculation.
When the modelled curve formula is known, it is advisable to use the curve parameters to achieve
maximum accuracy.
Events and registers
The capacitor bank overload function (abbreviated "COL" in event block names) generates events and
registers from the status changes in START, TRIP and BLOCKED. The user can select which event
messages are stored in the main event buffer: ON, OFF, or both. The function offers one (1)
independent stage.
The events triggered by the function are recorded with a time stamp and with process data values.
Table. 5.4.2.1 - 55. Event messages.
Event block name
Event names
COL1
Start On
COL1
Start OFF
COL1
Trip ON
COL1
Trip OFF
COL1
Block ON
COL1
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. 5.4.2.1 - 56. 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
5.4.2.2 Capacitor bank current unbalance protection (Iuc>; 46C)
The capacitor bank current unbalance protection is used in protecting the capacitor bank with a double
wye configuration. The operating decisions are based on phase current magnitudes which the function
constantly measures. The monitored phase current magnitudes are equal to RMS values. The blocking
signal and the setting group selection control the operating characteristics of the function during
normal operation, i.e. the user or user-defined logic can change function parameters while the function
is running.
The capacitor bank current unbalance function uses a total of eight (8) separate setting groups which
can be selected from one common source.
The function can operate on instant or time-delayed mode. The function includes CT saturation
checking which allows the function to start and operate accurately during CT saturation.
The operational logic consists of the following:
• input magnitude selection
• input magnitude processing
A
AQ
Q-C215
-C215
Instruction manual
Version: 2.07
© Arcteq Relays Ltd
IM00040
107