8.
Once again, wait until the stability criteria is fulfilled, then select the Submit button.
The result is stored for later calculations. ICT automatically shifts to the third calibration
tab, Step 3: Measurement 3.
If readings are not stable during the step, a warning to repeat the step
may be suggested; the step shall be repeated in order to avoid that the
calibration fails.
9.
Remove the known fault resistance attached earlier and apply a short circuit instead.
10. In the ICT toolbar, select the Start reading values from IED button.
The ICT performs consecutive measurements until the statistical error reaches an
acceptable value. This is graphically shown in a diagram.
11.
When the stability criteria are fulfilled, select the Submit button once again.
The result is stored for calculations. ICT automatically shifts to the fourth calibration tab,
Step 4: Save Calibration Factors. Here the newly calculated complex factors
k1 and k2 as
well as the reference impedance 1 are presented. The values of these parameters are
calculated by ICT on the basis of the three measurement steps described above.
If readings are not stable during the step, a warning to repeat the step
may be suggested; the step shall be repeated in order to avoid that the
calibration fails.
12.
ICT performs several checks on the measurement results of each steps in order to verify
that the change among measured impedances of the three steps is high enough (too low
changes may be related to a grounded system at the beginning of the calibration) and
that no problem affected the installation and calibration procedure.
Check the Calibration result field to make sure that all tests have been passed.
12.1. If a failure is indicated during one or more check(s), follow the instructions/tips
provided by the ICT in the Calibration result field.
12.2. If these tips do not solve the issue, then contact ABB Support.
Section 6
1MRK 502 067-UEN B
Calibrating injection based sensitive rotor earth fault protection
56
Commissioning manual
