ISA T 2000 - Mutual Factor Measurement

DOC. MIE11110 Rev. 5
Page
103
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110
In the average, the line argument is 80°. The ratio of output
voltage versus output current is equal to ZL + ZE; as ZL has been
measured, ZE can be derived. In the average, ZE = ZL.
- The test is performed on one line, that is short-circuited to
ground at the far end.
- Open SU3000. Connect one side to ground, and the other side to
two cables: one will go to T 2000, the other to the line to be
tested. Note that until SU3000 is OPEN, the switch is open, and
there is no ground connection.
- Close SU3000, close the switch: the cable is connected to
ground. Now you can connect to T 2000 output, and to the line,
that will be closed to ground.
- Connect to ground the other output of T 2000.
- SU3000 should now be opened, and the test can be started.
- Slowly increase the output voltage, and verify the corresponding
earth impedance ZE and argument, and also the earth factor KE
and the corresponding argument. As the impedance is the ratio
voltage versus current, its value should not change very much as
the current is increased. Note that the average value for KE is 1,
and its argument is 0°.
- Stop the test when values are stable; take care not to exceed
with the test current, otherwise you will be halted by an overload
message.
- When you are satisfied with the measurement, press SAVE.
- You can repeat the test with lines 1 and 3, to verify that the
measured ZL is the same.
- As you have finished, you can proceed with the measurement of
the mutual factor.
3.3 MUTUAL FACTOR MEASUREMENT
When this test is selected, the following menu is displayed.