CYG PRS-7367 User Manual

Protection Functions
PRS-7367 137
4
51NA_i_Curve_ParaA
0.000~120.000
0.01
0
Curve parameter A
5
51NA_i_Curve_ParaB
0.000~9.000
0.01
0
Curve parameter B
6
51NA_i_Curve_ParaC
0.0~1.0
0.01
2.00
Curve parameter C
7
51NA_i_Curve_ParaP
0.02~2.00
0. 1
1.0
Curve parameter P
8
51NA_i_Curve_ParaK
0.05-100
0.01
1
Curve parameter k
9
51NA_i_Min_Op_T
0.040-60.000
s
0.001
0.040
Minimum operation time
delay
10
51NA_i_Reset_T
0.000 -60.000
s
0.001
0.02
Reset time delay
11
51NA_i_Ena
0~1
1
0
Operation Enable/Disable
3.25 Three phase current unbalance protection 51NT
3.25.1 51NT Overview
The current unbalance protection for shunt capacitor banks function 51NT is used to protect the
Double-Y-connected capacitor banks from internal faults. 51NT is suitable for the protection of
internally fused, externally fused and fuse less applications. 51NT can be enabled or disabled and
it starts when the measured unbalance current exceeds the current startup setting. The operation
time characteristics can be selected to be either definite time (DT) or inverse definite minimum
time (IDMT).
3.25.1.1 Function Block
The function block of the protection is as below.
I3P
51NT
Blk
BlkStr
BlkOp
EnaMult
StrA
Op
StrB
StrC
Str
OpA
OpB
OpC
Figure 3.25-1 Function block
3.25.1.2 Signals
Table 3.25-1 Input Signals
Signal
Description
I3P
The current magnitude in all the three phases
Blk
This signal blocks all the binary output signals of the function

CYG PRS-7367 Specifications

General

Brand	CYG
Model	PRS-7367
Category	Control Unit
Language	English