ABB REL650 Applications Manual page 83

1MRK 506 334-UUS A
Application manual
Step 2- reach
Step 1- reach
A
REL 650
Y
ANSI11000115 V2 EN
Figure 27: Principle for four step residual overcurrent protection underreach
communication scheme
A communication signal is sent (CS) if a fault is detected by step 1 (3I
step). When a communication signal is received (CR) Step 2 (3I
instantaneously. The logic can be described as shown in figure 28.
EF4PTOC (51N_67N)
Step 1 PUST1
Step 2
Step 2
Receive signal (CR)
ANSI11000079 V1 EN
Figure 28: Logic for four step residual overcurrent protection underreach
communication scheme
This scheme is used for long lines where it can be assured that the zone 1 reach from both
line ends will overlap each other.
Z 1 = R 1 + jX 1
Z 0 = R 0 + jX0
Communication
Step 1- reach
Step 2- reach
Step 1 TRIP
TRIP
PUST2
REL650 setting examples
B
REL 650
C
Y
ANSI11000115_2_en.vsd
>>> underreach
0
>>) will operate
0
Send signal (CS)
OR
AND
ANSI11000079_1_en.vsd
Section 3
Trip
77