Tettex 2293 - Test Current Recommendations; Tap Sequence

Resistance Measurement
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The measuring current must be introduce
independent for each winding and is done in
the “measurement” folder clicking over the
Setup button in the function key bar.
A shortcut for current selection is available in the main screen; clicking in
the current by winding drawing
7.3.4 Test current recommendations
Normally 32 Amps are not necessary, except when really low resistances (<0.5mOhm) have to be
measured it can help to improve accuracy.
It is recommend to use 16A maximum. This way two windings of the transformer can be
measured simultaneously, which speeds up the measurement process a lot!
Current settings guideline
DUT type
Current
Distribution
HV = 1A .. 8A LV = 10A .. 16A
Power < 20MVA
HV = 4A .. 8A LV = 8A .. 16A
Power <200MVA
HV = 8A .. 16A LV = 12A .. 16A
Power >200MVA
HV = 16A LV = 16A
GSU (Generator Step Up):
HV = 16A LV = 16A
(with option "without R_Neutral")
Generally the resistance of the transformer winding to be measured is a good indicator for the
required measurement current:
< 10mΩ
16A
< 100mΩ
4A .. 12A
< 1Ω
2A .. 4A
< 10Ω
<1A
7.3.5 Tap sequence