ABB REL650 - Over-Reach Permissive Logic

• Power line carrier (PLC)
• Microwave link (radio)
• Optic fibre link
There are the following alternatives for communication scheme:
• Under-reach permissive logic
• Over-reach permissive logic
• Blocking scheme
1. Set SchemeType to Permissive OR
This corresponds to over-reach permissive scheme. The choice is based on the
following:
Permissive over-reach scheme is chosen because it is considered as the weak end
infeed logic shall be used as there is a risk of small current infeed. Th WEI function
requires permissive over-reach communication scheme.
2. Set tCoord to 0.000 s
3. Set tSendMin to 0.100 s
3.1.11.1 Over-reach permissive logic
The principle of the logic can be explained as shown in figure 25.
Z 1 = R 1 + jX 1
Z 0 = R 0 + jX0
A B
Step 1- reach
C
Communication
Step 2- reach
Step 1- reach
Step 2- reach
Y
Y
REL 650
REL 650
ANSI11000115_2_en.vsd
ANSI11000115 V2 EN
Figure 25: Principle for four step residual overcurrent protection overreach
communication scheme
1MRK 506 334-UUS A Section 3
REL650 setting examples
75
Application manual