CYG PRS-7367 - 51 NT Settings; Voltage Unbalance Protection 59 NA; 59 NA Overview

Protection Functions
PRS-7367 141
a failure of the healthy elements of the bank and in turn fail the entire capacitor bank.
3.25.4 51NT Settings
Table 3.25-3 51NT settings
No.
Name
Range
Unit
Step
Default
Description
1
51NT_Cur_Str
0.04-20.00In
A
0.01In
0.04In
Start current value
2
51NT_Mul_Cur
0.8 - 10.0
-
0.1
1
Multiplier current start
value
3
51NT_i_Curve_Type
0~5
-
1
0
0 Definite time
1 IEC Normal inverse
2 IEC Very inverse
3 IEC Extremely
inverse
4 IEC Long-time
inverse
5 Programmable
user-defined
4
51NT_Curve_ParaA
0.000~120.000
s
0.001
0
Curve parameter A
5
51NT_Curve_ParaB
0.000~9.000
s
0.001
0
Curve parameter B
6
51NT_Curve_ParaC
0.0~1.0
-
0.1
1.0
Curve parameter C
7
51NT_Curve_ParaP
0.02~2.00
-
0.01
2.00
Curve parameter P
8
51NT_Curve_ParaK
0.05-100
-
0.01
1.00
Curve parameter k
9
51NT_Min_Op_T
0.040-60.000
s
0.001
0.040
Minimum operation time
delay
10
51NT_Reset_T
0.000 -60.000
s
0.001
0.02
Reset time delay
11
51NT_Ena
0~1
-
1
0
Operation
Enable/Disable
12
51NT_Str_Ph_Num
1~3
/
1
1
Start current value
3.26 Voltage unbalance protection 59NA
3.26.1 59NA Overview
The voltage unbalance function 59NA monitors voltage unbalance conditions in power
transmission and distribution networks. It can be applied to identify a network and load unbalance
that can cause sustained voltage unbalance.