Pole Discrepancy Protection Ccrpld (52Pd) - ABB Relion Technical Manual

1MRK 502 048-UUS A
8.6
8.6.1
8.6.2
Technical manual
Function
Reset ratio
Timers
Operate time for current
detection
Reset time for current
detection

Pole discrepancy protection CCRPLD (52PD)

Identification
Function description
Pole discrepancy protection
Functionality
Circuit breakers and disconnectors can end up with their phases in different positions
(close-open), due to electrical or mechanical failures. 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 affected 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 pole discrepancy function operates based on information from the circuit breaker
logic with additional criteria from phase selective current unsymmetry.
Range or value
> 95%
(0.000-60.000) s
20 ms typically
10 ms maximum
IEC 61850
identification
CCRPLD
Section 8
Current protection
Accuracy
-
± 0.5% ±10 ms
-
-
IEC 60617 ANSI/IEEE C37.2
identification device number
52PD
PD
SYMBOL-S V1 EN
247