Pole Discrepancy Signaling From Circuit Breaker - ABB REL650 series Technical Manual

Section 7
Current protection
7.13.7.1
274
PD Signal from CB
EXTPDIND
CLOSECMD tTrip+200 ms
OR
OPENCMD
CB oper monitor
Unsymmetrical
current detection
ANSI08000014 V2 EN
Figure 129: Simplified block diagram of pole discrepancy function - contact and
current based
The pole discrepancy protection is blocked if the input signal BLOCK is high.
The BLOCK signal is a general purpose blocking signal of the pole discrepancy
protection. It can be connected to a binary input in the IED in order to receive a block
command from external devices or can be software connected to other internal functions
in the IED itself in order to receive a block command from internal functions. Through OR
gate it can be connected to both binary inputs and internal function outputs.
If the pole discrepancy protection is enabled, then two different criteria can generate a trip
signal TRIP:
• Pole discrepancy signaling from the circuit breaker.
• Unsymmetrical current detection.

Pole discrepancy signaling from circuit breaker

If one or two poles of the circuit breaker have failed to open or to close (pole discrepancy
status), then the function input EXTPDIND is activated from the pole discrepancy signal
in figure 128. After a settable time tTrip, a 150 ms trip pulse command TRIP is generated
by the pole discrepancy protection.
AND
AND
OR
AND
1MRK 506 335-UUS A
150 ms
0-Trip
0
ANSI08000014-2-en.vsd
Technical manual