ABB REL 551-C1 2.3 Series Installation And Commissioning Manual page 83

Definite and inverse time-delayed
residual overcurrent protection (TEF)
Table 10: Operate time formulas
Characteristics Operate time (s)
Normal inverse
t
Very inverse
t
Extremely inverse
t
Logarithmic inverse
t
Where:
I is a multiple of set current 3I
k is a time multiplying factor, settable in the range of 0.05 to 1.10
Also check the tMin (minimum operate time) and IMin (minimum
operate current) functions.
10. Activate the TEF--BC input to check the function of the
switch-onto-fault logic.
11. Check that the TEF--TRSOTF output is activated with a
300 ms time delay when injecting a current two times the set
IMin operate value in forward direction.
12. Set the phase angle of the polarising voltage to ϕ =245° and
check that the directional current function and the switch-
onto-fault logic gives no operation when the current is in the
reverse direction.
13. Connect the rated DC voltage to the TEF--BLOCK configured
binary input and switch on the fault current.
No TEF--TRIP nor TEF--START signal should appear.
14. Switch off the fault current.
0.14
------------------- - k ⋅
=
0.02
I 1
–
13.5
---- ------- k ⋅
=
I 1
–
80
------------- k ⋅
=
2
I – 1
( ⋅ )
= 5.8 – 1.35 ln I
>
0
Chapter 11
Verifying settings by secondary
injection
(Equation 1)
(Equation 2)
(Equation 3)
(Equation 4)
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