Compact current relay and
protection assemblies
RXHL 401 and
RAHL 401
1MRK 509 062-BEN
Page 16
Table 16: Time functions for earth-fault protection
Influence of har-
monics
100/120 Hz, 10%
< 2%
150/180 Hz, 20%
< 6%
250/300 Hz, 20%
< 3%
Temperature dependency within range -5° C to
+55° C
< 2%
Time function
Stage I
N
>
Stage I
N
>>
Stage I
N
>>>
Time delay
Inverse, definite or log-
arithmic time (NI, VI, EI,
LI, RI and Log)
Definite
time
Definite time
Setting range, definite time
0-20 s
Accuracy, definite time
+/-30 ms
Setting range, inverse time
k = 0.05-1.1
-
-
Min time, inverse time
0-2.0 s
-
-
Accuracy,
inverse
time
a)
NI, VI,
EI, LI
b)
2.0 x I>
set
12.5% and +/-30 ms
-
-
5.0 x I>
set
7.5% and +/-30 ms
10.0 x I>
set
5% and +/-30 ms
20.0 x I>
set
5% and +/-30 ms
RI
1.0-1.3 x I>
set
12.5% and +/-30 ms
1.3-20.0 x I>
set
5% and +/-30 ms
Setting range, logarithmic time (IDG)
k = 1-4
-
-
Min time, logarithmic time
1.0-2.0 s
-
-
Formula, logarithmic time
t = 5.8-1.35 x In (I/I
Nset
)
-
-
Accuracy, logarithmic time
+/-50 ms overall
-
-
Linear reset time
0-500 s
-
-
a)
A percentage value of theoretical time and a definite time delay
b)
According to IEC 60255-3, signed error 5
Earth-fault protection
Stage I
N
>
Stage I
N
>>
Stage I
N
>>>
