ABB Relion 650 Series Technical Manual page 165

1MRK 506 326-UUS B
ANSI09000636 V1 EN-US
Figure 87: Directional characteristic of the phase overcurrent protection
1 RCA = Relay characteristic angle 55°
2 ROA = Relay operating angle 80°
3 Reverse
4 Forward
If no blockings are given the pickup signals will start the timers of the step. The time characteristic
for step 1 and 4 can be chosen as definite time delay or inverse time characteristic. Step 2 and 3
are always definite time delayed. A wide range of standardized inverse time characteristics is
available. The possibilities for inverse time characteristics are described in section
characteristics".
All four steps in OC4PTOC (51/67) can be blocked from the binary input BLOCK. The binary input
BLKx (x=1, 2, 3 or 4) blocks the operation of respective step.
Line distance protection REL650
Technical manual
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Section 6
Current protection
"Inverse time
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