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