Tettex MIDAS 2881, Operating Instructions Manual

Page: 152 / 164

142 Applications Guide
Measurement on an ungrounded two-bushing energy storage capacitor, connection for
determination of C
G1
+ C
G2
C
1
: main capacitor
C
G1
, C
G2
: earth insulation capacitance
Test Connections
DUT High Voltage
to INPUT A
to HV GND
to Test Mode
C
1
1 2 GND UST A
C
G1
1 2 Tank GND GST gA+B
C
G2
2 1 Tank GND GST gA+B
C
G1
+ C
G2
1 + 2 Tank GND UST A
14.6.1 Measuring high cap values using the Resonating Inductor
With the MIDAS built-in supply, capacitances up to a maximum of C
X
= 100nF (
@
50/ 60Hz, S
max
3kVA) can be measured. For capacitances with higher values the test voltage has to be reduced or a
parallel resonating circuit can be created by using the optional resonating inductor (see also chapter
“Application Guide : Measuring high cap values using the Resonating Inductor”).
The arrangement MIDAS with resonating inductor 5288 enables measurement of capacitances up to
1
μ F (15 kV
@
50 / 60 Hz, S
max
3kVA). For a functional description and further explanations see
chapter "Accessories and Options:Resonating Inductor".