EDS470 - Bender

Operating principle of the EDS470 sy stem
FAULT curve
The possible frequency range is shown by the curve (FAULT curve) which
follows. This indicates the range in which residual currents are displayed as a
FAULT. In general, residual currents > 10 A are displayed accordingly, and
independently of the frequency.
Outside of the admissible range, PEAK-FAULT messages may be signalled if
residual currents occur. Likewise, excessively high leakage capacitances can lead
to PEAK-FAULT messages.
Residual Current (A)
Differenzsztrom (A)
10
9
8
7
6
5
4
3
2
1
0
Fault curve
Fault-Kurve
Indication FAULT > 10 A
Indication Peak FAULT
Admissible range
1
4
7
12
20
25
30
40
46
54
Frequency Frequenz (Hz) (Hz)
60
75
100
130
400
Reihe1
EDS470 electrical interference. The curve indicates the residual current maximum before a
PEAK-FAULT message is given.
A sophisticated filter circuit and electronic system avoids malfunctions due to
extraneous currents < 10 A.
The FAULT LED is located in the front panel of the EDS470-12. It flashes to
indicate the following states:
• Short-circuited current transformer connection. The EDS system omits this
current transformer subcircuit and continues with the subsequent one.
• Interrupted current transformer connecting lead, or no current transformer
connected. The EDS system omits this current transformer subcircuit and
continues with the subsequent one.
• A residual current > 10 A through the current transformer. The EDS
system omits this current transformer subcircuit and continues with the
subsequent one.
• The current transformer signal cannot be evaluated due to interferences.
The EDS system makes n attemps to take a measurement at this current
transformer subcircuit. In this case, n is the number of scanning cycles
which has been set (PEAK) in menu 10 of the PRC470 (refer to the
chapter on SETTINGS AND ADJUSTMENTS).
• The leakage capacitances in the system, or in an subcircuit of the system,
are too high.
The FAULT LED itself does not distinguish which of the faults listed above has
actually occurred. This information can be obtained from menu 5 (POSITION) of
the PRC470. In the event of a short-circuited or interrupted current transformer
connection, no explanation of the FAULT message will be given. Residual
currents > 10 A are indicated by the display ”ID > 10 A”, and current transformer
signals which cannot be evaluated are indicated by the display ”PEAK”.
12
TGH 1243E/02.2000