Visual Inspection; Maintenance Tests - ABB RET650 Series Commissioning Manual

Section 8
Commissioning and maintenance of the fault clearing system
Every four to six years
• Periodic maintenance test for protection IEDs of objects with redundant protection system.
8.1.2.1

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). Should burned contacts be
observed when inspecting the IEDs, a diamond file or an extremely fine file can be used to polish
the contacts. Emery cloth or similar products must not be used as insulating grains of abrasive
may be deposited on the contact surfaces and cause failure.
Make sure that all IEDs are equipped with covers.
8.1.2.2

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 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.
Important components of FT test system are FT1, FTx, FT19, FT19RS, FR19RX switches and
assemblies as well as FT-1 test plug.
Preparation
Before starting maintenance testing, the test engineers should scrutinize applicable circuit
diagrams and have the following documentation available:
88
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.
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