ABB Relion 670 Series Technical Reference Manual page 471

1MRK505222-UUS C
7.9.6
7.10
7.10.1
Technical reference manual
Technical data
Table 228: STBPTOC (50STB) technical data
Function
Operating current
Reset ratio
Definite time
Operate time, pickup
function
Reset time,
pickupfunction
Critical impulse time
Impulse margin time
Pole discrepancy protection CCRPLD (52PD)
Function description
Pole discrepancy protection
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.
Range or value
IBase
(1-2500)% of
> 95%
(0.000-60.000) s
20 ms typically at 0 to 2 x I
set
25 ms typically at 2 to 0 x I
set
10 ms typically at 0 to 2 x I
set
15 ms typically
IEC 61850
identification
CCRPLD
Section 7
Current protection
Accuracy
± 1.0% of I at I £ I
n n
± 1.0% of I at I > I
n
-
± 0.5% ± 10 ms
-
-
-
-
IEC 60617 ANSI/IEEE C37.2
identification device number
52PD
PD
SYMBOL-S V1 EN
465