ISA T 2000 - 2: PT Tests: Resistance of LTC Contacts

DOC. MIE11110 Rev. 5
Page
72
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110
HV cables shall be connected while T 2000 is powered-off. HV
clamps shall have a minimum clearance of 20 mm with respect to
all conductive surfaces, so to avoid discharges during operation.
After connections, the area around the HV clamps shall be
isolated, so that no accidental contact can occur. If something
goes wrong for any reason, power-off T 2000 before getting close
to HV connections.
As the test is to be performed on the 3000 V range, press test
START button (56): the following message will be displayed.
The HV is generated only while the START button (56) is kept
pressed: this is an additional safety feature. The operator will
have both hands occupied: one for the knob (6), the other for the
button (56); however, this is much safer than starting the HV
generation, and then forgetting it in the ON state.
You have to turn ON the HV key (28), and adjust the VSEC
voltage to the nominal voltage, if it is less then 3000 V, or aT
2000 V, by the adjustment knob (6); the screen shows:
. The applied primary voltage;
. The primary current;
. The phase shift of the secondary voltage with respect to the
primary voltage;
. The measured secondary voltage;
. The transformer ratio;
. The percentage ratio error with respect to the nominal.
When you are satisfied of the result, press SAVE: test result is
saved. Return to zero the adjustment knob (6), and turn off the
HV key (28); then press the STOP key.
1.3.2: PT tests: resistance of LTC contacts
When this test is selected, the following menu is displayed.