Principle For Delta Blocking Scheme - ABB REL650 Applications Manual

Section 3
REL650 setting examples
3.1.6.4
62
ZQMPDIS (21)
Zone 1 TRIP
Zone 1 PICKUP
Zone 2 TRIP
Zone 2 PICKUP
Receive signal ( CR)
Reverse :
Zone 4 TRIP
Zone 4 PICKUP
ANSI11000077 V2 EN
Figure 17: Logic of blocking communication scheme
The trip signal from zone 2 must be delayed so that the blocking signal has enough time
for blocking at external faults.

Principle for delta blocking scheme

The principle of the logic can be explained as shown in figure 18.
1MRK 506 334-UUS A
OR
AND
Send signal (CS)
ANSI11000077_2_en.vsd
Application manual
Trip