Tettex MIDAS 2881, Руководство по эксплуатации

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Applications Guide 131
Excitation current measurement connection for L
XP3
and L
XP2
measurement on a D-Yn transformer
Test Connections
DUT, excitation
current through High Voltage
to INPUT A
to INPUT B
to HV GND INPUT
to Test Mode
L
XP3
1 3 2 Tank GND UST A
L
XP1
1 3 2 Tank GND UST B
L
XP2
2 3 1 Tank GND UST A
L
XS1
4 7 - Tank GND UST A
L
XS2
5 7 - Tank GND UST A
L
XS3
6 7 - Tank GND UST A
Measuring Data Interpretation
On a three-phase, star/delta or delta/star transformer, the excitation current pattern will generally be
higher on two phases than on the remaining phase. The lower current in a phase can be attributed to
the lower reluctance of the magnetic circuit for the center leg of a three-legged core.
Excitation current
<
50 mA
Excitation current

50 mA