VERY IMPORTANT NOTICE: during the current adjustment, a
current is induced into the primary loop, that is short-circuited:
the induced current is a function of the current rate of change.
For this reason, the test current MUST BE INCREASED VERY
SLOWLY: the current is delayed with respect to the voltage.
When the desired test current is reached, it is necessary to wait
for a while until the resistance measurement stabilizes. After
SAVE, DECREASE THE CURRENT VERY SLOWLY TO ZERO. The time
should be not less then 10 s for increasing and reducing the
current.
If you press STOP when the adjustment knob is not at zero, the
following message is displayed, AND THE CURRENT IS NOT
REMOVED:
You have to move the knob to zero, then press STOP; for some
time, until the magnetization energy is not discharged and some
current flows into the discharger, the following message is
displayed:
DO NOT PERFORM THE TEST WITHOUT THE PRIMARY SHORT-
CIRCUIT: AT THE END OF THE TEST, THE TRANSFORMER WOULD
BE LEFT WITH A REMANENT MAGNETIZATION.
DO NOT REMOVE THE CONNECTION UNTIL THE MESSAGE
DISAPPEARS! If you do, the residual energy would cause an
high voltage spark on the conductor you are removing.
1.3.3: PT tests: dynamic LTC test
The operating principle of this test is explained in Appendix. When
this test is selected, the following menu is displayed.
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