• Visual inspection of all equipment.
• Removal of dust on ventilation louvres and IEDs if necessary.
• Periodic maintenance test for protection IEDs of object where no redundant
protections are provided.
Every four to six years
• Periodic maintenance test for protection IEDs of objects with redundant protection
system.
First maintenance test should always be carried out after the first half year
of service.
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
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
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 or FT test systems 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.
Section 14 1MRK 504 165-UUS -
Commissioning and maintenance of the fault clearing system
298 Transformer protection RET670 2.2 ANSI
Commissioning manual
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