90
Definite and inverse time-delayed
residual overcurrent protection (TEF)
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LQMHFWLRQ
7DEOH 2SHUDWHWLPHIRUPXODV
Also check the tMin (minimum operate time) and IMin (minimum
operate current) functions.
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VZLWFKRQWRIDXOWORJLF
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,0LQRSHUDWHYDOXHLQIRUZDUGGLUHFWLRQ
6HWWKHSKDVHDQJOHRIWKHSRODULVLQJYROWDJHWR
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FKHFNWKDWWKHGLUHFWLRQDOFXUUHQWIXQFWLRQDQGWKHVZLWFK
RQWRIDXOWORJLFJLYHVQRRSHUDWLRQZKHQWKHFXUUHQWLVLQWKH
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ELQDU\LQSXWDQGVZLWFKRQWKHIDXOWFXUUHQW
No TEF--TRIP nor TEF--START signal should appear.
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Normal inverse
(Equation 1)
Very inverse
(Equation 2)
Extremely inverse
(Equation 3)
Logarithmic inverse
(Equation 4)
Where:
I
is a multiple of set current 3I
0
>
k
is a time multiplying factor, settable in the range of 0.05 to 1.10
t
0.14
I
0.02
1
–
--------------------
k
⋅
=
t
13.5
I
1
–
-----------
k
⋅
=
t
80
I
2
1
–
-------------
k
⋅
=
t
5.8
1.35
I
ln
⋅
(
)
–
=
Summary of Contents for REL 531
Page 16: ...10 Note signs KDSWHU 6DIHW LQIRUPDWLRQ ...
Page 44: ...38 Checking the binary I O circuits KDSWHU KHFNLQJ WKH H WHUQDO FLUFXLWU ...
Page 52: ...46 Checking the self supervision signals KDSWHU QHUJLVLQJ WKH WHUPLQDO ...
Page 140: ...134 Testing the interaction of the distance protection KDSWHU 7HVWLQJ WKH SURWHFWLRQ V VWHP ...