Schweitzer Engineering SEL-387-0 - Figure 3.11 REF Enable;Block Logic; Figure 3.12 REF Directional Element

3.26
SEL-387-0, -5, -6 Relay Instruction Manual Date Code 20170601
Differential, Restricted Earth Fault, Thermal, and Overcurrent Elements
Restricted Earth Fault Element
Figure 3.11 REF Enable/Block Logic
Figure 3.12 illustrates the logic of the REF directional element, 32I. It is at
this stage that the element decides whether to operate.
Figure 3.12 REF Directional Element
The relay enables the 32I directional element if the output of the AND gate at
left-center in Figure 3.12 asserts. This will occur if the two Relay Word bits
32IE and 50GC assert.
_
+
_
+
_
+
_
+
_
+
_
+
50GP
32IOP = 1,12,123
32IOP = 2,12,123,23
32IOP = 3,123,23
|IRW4|
_
+
50G4 (Relay Word bit)
CTR1
CTR4
CTR2
CTR4
CTR3
CTR4
IRW1
IRW2
IRW3
32IOP = 1,12,123
32IOP = 2,12,123,23
32IOP = 3,123,23
32IE
CTS
E32I
(SEL
OGIC control equation)
_
+
50GC
Relay
Word
Bits
50GP
0.8
∑
a
0
|I
1W1
|
a
0
|I
1W2
|
a
0
|I
1W3
|
|I
0W2
|
|I
0W1
|
|I
0W3
|
|IRW1|
|IRW2|
|IRW3|
CTR1
CTR2
IRW1
IRW2
32IOP = 1,12,123
32IOP = 2,12,123,23
32IOP = 3,123,23
IRW3
CTR3
IRW4
CTR4
I
OP
I
POL
RE(Iop • Ipol*)
32IE
50GC
+
_
+
_
Pos.
Threshold
Neg.
Threshold
1.5
cyc
0
1.5
cyc
0
32IF
32IR
∑
Relay
Word
Bits
Relay
Word
Bits