Section 7 Commissioning and maintenance of thefault clearing system7.1 Commissioning and maintenance of the fault clearingsystemAbout this chapterThis chapter discusses maintenance tests and other periodic maintenance measures.7.1.1 Commissioning testsDuring commissioning all protection functions shall be verified with the settingvalues used at each plant. The commissioning tests must include verification of allcircuits by green-lining the circuit diagrams and the configuration diagrams for theused functions.Further, the settings for protection functions are tested and recorded carefully asoutlined for the future periodic maintenance tests.The final testing includes primary verification of all directional functions where loadcurrents is checked on the local HMI and in PCM600. The amplitudes and angles ofall currents and voltages should be checked and the symmetry verified.Directional functions have information about the measured direction and, forexample, measured impedance. These values must be checked and verified as correctwith the export or import of power available.Finally, final trip tests must be performed. This involves activation of protectionfunctions or tripping outputs with the circuit breaker closed and the tripping of thebreaker verified. When several breakers are involved, each breaker must be checkedindividually and it must be verified that the other involved breakers are not tripped atthe same time.7.1.2 Periodic maintenance testsThe periodicity of all tests depends on several factors, for example the importance ofthe installation, environmental conditions, simple or complex equipment, static orelectromechanical IEDs, and so on.The normal maintenance praxis of the user should be followed. However, ABB'srecommendation is as follows:1MRK 502 049-UEN A Section 7Commissioning and maintenance of the fault clearing system113Commissioning manual
