When protection IEDs are combined with built-in control, the test interval can
be increased drastically, up to for instance 15 years, because the IED
continuously reads service values, operates the breakers, and so on.
14.2.1
Visual inspection
SEMOD56525-5 v3
Prior to testing, the protection IEDs should be inspected to detect any visible damage that
may have occurred (for example, dirt or moisture deposits, overheating).
Make sure that all IEDs are equipped with covers.
14.2.2
Maintenance tests
SEMOD56534-1 v1
SEMOD56528-5 v5
To be made after the first half year of service, then with the cycle as proposed above and after
any suspected maloperation or change of the IED setting.
Testing of protection IEDs shall preferably be made with the primary circuit de-energized. The
IED cannot protect the circuit during testing. Trained personnel may test one IED at a time on
live circuits where redundant protection is installed and de-energization of the primary circuit
is not allowed.
ABB protection IEDs are preferably tested by aid of components from the COMBITEST testing
system described in information B03-9510 E. Main components are RTXP 8/18/24 test switch
usually located to the left in each protection IED and RTXH 8/18/24 test handle, which is
inserted in test switch at secondary testing. All necessary operations such as opening of trip
circuits, short-circuiting of current circuits and opening of voltage circuits are automatically
performed in the right order to allow for simple and safe secondary testing even with the
object in service.
14.2.2.1
Preparation
SEMOD56528-10 v2
Before starting maintenance testing, the test engineers should scrutinize applicable circuit
diagrams and have the following documentation available:
•
Test instructions for protection IEDs to be tested
•
Test records from previous commissioning and maintenance tests
•
List of valid settings
•
Blank test records to fill in measured values
14.2.2.2
Recording
SEMOD56528-14 v2
It is of utmost importance to carefully record the test results. Special test sheets covering the
frequency of test, date of test and achieved test values should be used. IED setting list and
protocols from previous tests should be available and all results should be compared for
differences. At component failures, spare equipment is used and set to the requested value. A
note of the exchange is made and the new measured values are recorded. Test records for
several years of testing should be stored in a common file for a station, or a part of a station,
to give a simple overview of the period of testing and achieved test values. These test records
are valuable when analysis of service disturbances shall be done.
14.2.2.3
Secondary injection
SEMOD56528-17 v2
The periodic maintenance test is done by secondary injection from a portable test set. Each
protection shall be tested according to the secondary injection test information for the
Section 14
1MRK 502 067-UEN B
Commissioning and maintenance of the fault clearing system
236
Commissioning manual
