Operation Manual

MI 3121H Smartec 2,5 kV Insulation / Continuity Insulation resistance
23
Figure 5.4: Example of insulation resistance measurement result
Displayed results:
Insulation resistance – value,
Insulation resistance – analog presentation,
Test voltage – actual value.
Test voltage – nominal value.
5.1.2 The DAR and PI diagnostic
The DAR and PI diagnostic is automatically calculated during insulation measurements.
DAR is ratio of Insulation Resistance values measured after 15s and after 1 minute. The
DC test voltage is present during the whole period of the measurement.
When internal timer reaches 15 seconds, R
ISO
(15s) is stored into the internal memory
(short beep is generated).
When internal timer reaches 1 minute, R
ISO
(1min) is stored into the internal memory (short
beep is generated). The DAR factor is calculated and stored into the internal memory. The
DAR icon becomes also active to signalize during measurement, that DAR factor has
been calculated.
(
)
()
s
DAR
R
R
iso
iso
15
min1
=
PI is the ratio of Insulation Resistance values measured after 1 minute and after 10
minutes. The DC test voltage is present during the whole period of the measurement
When internal timer reaches 10 minute, R
ISO
(10min) is stored into the internal memory
(short beep is generated). The PI factor is calculated and stored into the internal memory.
The PI icon becomes also active to signalize during measurement, that PI factor has been
calculated.
(
)
()
min1
min10
R
R
iso
iso
PI =
It is possible to switch between DAR, PI and insulation results during measurement by
pressing the TAB key. See the Figure 5.5 and Figure 5.6.