MI 3152(H)
Eurotest
XC (2,5 kV)
Tests and measurements
95
7.3
The DAR and PI diagnostic (MI 3152H only)
DAR
(
D
ielectric
A
bsorption
R
ation) is ratio of insulation resistance values measured after 15
seconds and after 1 minute. The DC test voltage is present during the whole period of the
measurement.
𝐷𝐴𝑅 =
𝑅
𝐼𝑆𝑂
(1 min)
𝑅
𝐼𝑆𝑂
(15 s)
PI
(
P
olarization
I
ndex) 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
𝑃𝐼 =
𝑅
𝐼𝑆𝑂
(10 min)
𝑅
𝐼𝑆𝑂
(1 min)
For additional information regarding PI and DAR
diagnostic, please refer to Metrel’s handbook
Modern insulation testing
.
Figure 7.10: Diagnostic test menu
Measurement parameters / limits
Uiso
Nominal test voltage
[500 V, 1000 V, 2500 V]
Connection diagrams
Figure 7.11: Connection of 3-wire test lead and Tip commander (U
N
≤ 1 kV)
