Visual Inspection; Maintenance Tests - ABB RET670 Installation And Commissioning Manual

1MRK 504 088-UEN C
15.3.1
15.3.2
Installation and commissioning manual
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.
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.

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.

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 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.
Section 15
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