8.13.8
Technical data
SEMOD171939-1 v1
SEMOD175200-2 v7
Table 298: BRCPTOC (46) technical data
Function
Range or value
Accuracy
Minimum phase current for operation
(5–100)% of
IBase
±1.0% of I
n
Unbalance current operation
(50–90)% of maximum current
±1.0% of I
n
Independent trip time delay
(0.000-60.000) s
±0.2% or ±45 ms whichever is greater
Independent reset time delay
(0.010-60.000) s
±0.2% or ±30 ms whichever is greater
Pickup time at current change from I
n
to 0
Min. = 25 ms
Max. = 35 ms
-
Reset time at current change from 0 to
I
n
Min. = 5 ms
Max. = 20 ms
-
8.14
Negativ sequence time overcurrent protection for
machines NS2PTOC (46I2)
GUID-25821361-229A-44BB-A60F-FC6DD9F4F140 v2
8.14.1
Identification
GUID-19BB1653-55AE-44D1-B964-F59AED5350C4 v3
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Negative sequence time overcurrent
protection for machines
NS2PTOC
2I2>
46I2
8.14.2
Functionality
GUID-DBF3EC07-D947-4483-ABD1-4F7D29F48D61 v6
Negative-sequence time overcurrent protection for machines NS2PTOC (46I2) is intended
primarily for the protection of generators against possible overheating of the rotor caused by
negative sequence current in the stator current.
The negative sequence currents in a generator may, among others, be caused by:
•
Unbalanced loads
•
Line to line faults
•
Line to ground faults
•
Broken conductors
•
Malfunction of one or more poles of a circuit breaker or a disconnector
NS2PTOC (46I2) can also be used as a backup protection, that is, to protect the generator in case
line protections or circuit breakers fail to clear unbalanced system faults.
To provide an effective protection for the generator for external unbalanced conditions, NS2PTOC
(46I2) is able to directly measure the negative sequence current. NS2PTOC (46I2) also has a time
1MRK 502 066-UUS B
Section 8
Current protection
561
Technical manual
Summary of Contents for Relion 670 series
Page 1: ... RELION 670 SERIES Generator protection REG670 Version 2 1 ANSI Technical manual ...
Page 2: ......
Page 48: ...42 ...
Page 62: ...56 ...
Page 182: ...176 ...
Page 692: ...686 ...
Page 726: ...720 ...
Page 1014: ...1008 ...
Page 1242: ...1236 ...
Page 1362: ...1356 ...
Page 1386: ...1380 ...
Page 1422: ...1416 ...
Page 1431: ...1425 ...