Data
72
TGH1394en/05.2007
The following characteristics are an easy way of determining a suitable
response value for the insulation monitoring device and the EDS... . Pro-
ceed as follows:
1. Select the characteristics (3 AC, AC, DC) that are appropriate for your
type of distribution system.
2. From these, select the diagram that best matches the desired system
voltage.
3. Calculate the anticipated leakage capacitance of the system being
monitored. The IRDH575 displays the system leakage capacitance
(press the INFO key). Apply this value to the diagram in the form of a
vertical line.
4. The characteristics provided indicate the EDS system's response sensi-
tivity when the EDS response value is set to 2 mA, 5 mA and 10 mA. Val-
ues above the relevant curve cannot be detected.
5. Select the middle characteristic for an EDS... response value of 5 mA
(factory setting). Mark the system leakage capacitance C
e
on the char-
acteristic. Read off the relevant resistance R from the characteristic. The
resistance R thus calculated indicates the maximum response value
that can be set on the insulation monitoring device (e.g. IRDH575). If
higher response values than this are set, insulation fault detection
becomes unreliable. A reliable response on the part of the insulation
monitoring device must be ensured before the EDS system can be
started.
6. If you wish to set a higher or lower response value for the insulation
monitoring device, you will need to calculate the resistance (R) for the
top and bottom characteristics as described under point 5. Values and
characteristics that fall between the top and bottom characteristics can
be roughly determined on the basis of those actually provided.
7. Set the calculated response values on the insulation monitoring device
and the EDS... .
To Next Page
Loading...