Step 5: Automatic And Manual Ct Detection Procedure; Automatic Ct Detection Procedure - ABB PQFS Installation, Operation And Maintenance Instructions

requirement is low), the system clock, the external communication protocol
(Modbus or PC) and the software lock, refer to
full redundancy for the communication features in master-master filters, this
function has to be cabled to all master units and all the PQF-Managers have to be
set up accordingly.
If the CTs have been set up correctly at this stage, go to step 6
Otherwise, consult go to step 5 for background information on the automatic and
manual CT detection procedure.

8.6 Step 5: Automatic and manual CT detection procedure

WARNING: Do not filter harmonics or do reactive power compensation/balancing
when the CTs have not been set up correctly. Failure to adhere to this guideline will
result in erratic filter operation.
Refer to Section 6.9
WARNING: Before programming or detecting the CTs, make sure that:
− The CTs have been connected to the filter CT terminal X21. For multi-filter
configurations all the units of a filter system have to be supplied with the same CT
information (daisy chain principle with return path as shown in
− All shorting links in the CT path have been removed (i.e. on the CTs, on the filter CT
terminal X21 ...).
CT shorting links are provided with the filter for servicing purposes, but they are not
installed by default on the X21 terminal.
The CT settings can be detected with the automatic CT detection feature or in a
conventional way. The automatic CT detection approach allows compensating for
physical connection errors in software. For multi-unit filters, the automatic CT detection
feature will automatically try and detect the CT-connections for the different units.
8.6.1

Automatic CT detection procedure

The automatic CT detection procedure and the precautions to take when using it are
explained in detail in
Section 8.6.2 discusses a way to check the CT installation if the automatic CT detection
procedure is not used or does not find the correct results.
NOTE: When the automatic CT detection procedure is started, the filter will
automatically deactivate all user requirements for filtering, reactive power
148 Commissioning instructions  Manual Power Quality Filter PQFS
and Section 6.10 for the CT selection and installation guidelines.
Section 7.9.2.3.1.
Section 7.9.3. In order to achieve
(Section 8.7).
Figure 38).