ABB Relion 620 Series - Current Unbalance Protection for Capacitor Banks CUBPTOC

4.12.1.9 Technical data
Table 746: COLPTOC Technical data
Characteristic Value
Operation accuracy Depending on the frequency of the measured current: f
n
±2 Hz, and no
harmonics
5 % of the set value or 0.002 × I
n
Start time for overload stage
1
,
2
Typically 75 ms
Start time for under current stage
2
,
3
Typically 26 ms
Reset time for overload and alarm stage Typically 60 ms
Reset ratio Typically 0.96
Operate time accuracy in definite time mode 1 % of the set value or ±20 ms
Operate time accuracy in inverse time mode 10 % of the theoretical value or ±20 ms
Suppression of harmonics for under current
stage
DFT: -50 dB at f = n × fn, where n = 2,3,4,5,..
4.12.1.10 Technical revision history
Table 747: COLPTOC Technical revision history
Technical revision Change
B Internal improvement.
4.12.2 Current unbalance protection for capacitor banks
CUBPTOC
4.12.2.1 Identification
Table 748: Function identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Current unbalance protection for
shunt capacitor banks CUBPTOC dI>C 51NC-1
4.12.2.2 Function block
Figure 410: Function block symbol
1
Harmonics current before fault = 0.5 × I
n
, harmonics fault current 1.5 × Start value , results based
on statistical distribution of 1000 measurements
2
Includes the delay of the signal output contact
3
Harmonics current before fault = 1.2 × I
n
, harmonics fault current 0.8 × Start value , results based
on statistical distribution of 1000 measurements
Protection functions 1MRS757644 H
782 620 series
Technical Manual