ISA T 2000 - CT Tests: Voltage Withstand

DOC. MIE11110 Rev. 5
Page
50
of
110
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 .1.7. CT tests : voltage withstand
When this test is selected, the following menu is displayed.
Purpose of the test is to verify the isolation of the CT secondary
cabling (and of the CT secondary itself), and to measure the
corresponding leakage current (typically capacitive).
This test is performed applying the high voltage between
secondary cablings and ground, and measuring the corresponding
current sink. It is also possible to test the insulation between
primary and secondary, and between primary and ground;