8.9.2
Functionality
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 persists
the surrounding breakers should be tripped to clear the unsymmetrical load situation.
The Pole discordance protection function CCPDSC operates based on information
from auxiliary contacts of the circuit breaker for the three phases with additional
criteria from unsymmetrical phase currents when required.
8.9.3
Function block
CCPDSC
I3P*
BLOCK
BLKDBYAR
CLOSECMD
OPENCMD
EXTPDIND
POLE1OPN
POLE1CL
POLE2OPN
POLE2CL
POLE3OPN
POLE3CL
TRIP
START
IEC13000305-1-en.vsd
IEC13000305 V1 EN
Figure 189:
CCPDSC function block
8.9.4
Signals
Table 207:
CCPDSC Input signals
Name
Type
Default
Description
I3P
GROUP
SIGNAL
-
Three phase currents
BLOCK
BOOLEAN
0
Block of function
BLKDBYAR
BOOLEAN
0
Block of function at CB single phase auto re-closing
cycle
CLOSECMD
BOOLEAN
0
Close order to CB
OPENCMD
BOOLEAN
0
Open order to CB
EXTPDIND
BOOLEAN
0
Pole discordance signal from CB logic
POLE1OPN
BOOLEAN
1
Pole one opened indication from CB
POLE1CL
BOOLEAN
0
Pole one closed indication from CB
POLE2OPN
BOOLEAN
1
Pole two opened indication from CB
POLE2CL
BOOLEAN
0
Pole two closed indication from CB
POLE3OPN
BOOLEAN
1
Pole three opened indication from CB
POLE3CL
BOOLEAN
0
Pole three closed indication from CB
Section 8
1MRK502052-UEN B
Current protection
414
Technical manual
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