Manual MRG3
SEG Electronics GmbH
DOK-TD-MRG3, Rev. D
73
7.5 Measuring input: Earth current
Rated data:
Nominal current I
N
1A or 5A
Nominal frequency f
N
50/60 Hz adjustable
Measuring range:
MRG3-IE:
0
– 4.0 x I
N
MRG3-IER:
0
– 0.5 x I
N
Measuring accuracy:
±3% from measuring value or ±20mA
Power consumption in current circuit: bei I
N
= 1 A
0,2 VA
bei I
N
= 5 A
0,1 VA
Thermal withstand capability
In current circuit:
dynamic current withstand
(one halfwave)
250 x I
N
for 1 s
100 x I
N
for 10 s
30 x I
N
continuously
4 x I
N
Dropout to pickup ratio:
MRG3-IE
95%
MRG3-IER
97%
Returning time:
100 ms
Minimum operating time:
100 ms
7.5.1 Influences on the earth current measuring
Auxiliary voltage
in the range 0.8 < U
H
/U
HN
< 1.2
no additional influences can be measured
Frequency:
Only the first harmonic is evaluated. Harmonic waves are
suppressed.
Influences on delay times:
no additional influences can be measured