ABB Relion 670 series, Technical Reference Manual

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7.9.6 Technical data
Table 228: STBPTOC (50STB) technical data
Function Range or value Accuracy
Operating current (1-2500)% of IBase
±
1.0% of I
n
at I
£
I
n
± 1.0% of I at I > I
n
Reset ratio > 95% -
Definite time (0.000-60.000) s
±
0.5%
±
10 ms
Operate time, pickup
function
20 ms typically at 0 to 2 x I
set
-
Reset time,
pickupfunction
25 ms typically at 2 to 0 x I
set
-
Critical impulse time 10 ms typically at 0 to 2 x I
set
-
Impulse margin time 15 ms typically -
7.10 Pole discrepancy protection CCRPLD (52PD)
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Pole discrepancy protection CCRPLD
PD
SYMBOL-S V1 EN
52PD
7.10.1 Introduction
An open phase can cause negative and zero sequence currents which cause thermal
stress on rotating machines and can cause unwanted operation of zero sequence or
negative sequence current functions.
Normally the own breaker is tripped to correct such a situation. If the situation
warrants the surrounding breakers should be tripped to clear the unsymmetrical load
situation.
The Polediscrepancy protection function CCRPLD (52PD) operates based on
information from auxiliary contacts of the circuit breaker for the three phases with
additional criteria from unsymmetrical phase currents when required.
1MRK505222-UUS C
Section 7
Current protection
465
Technical reference manual