5.4 Arc protection ARCSARC5.4.1 IdentificationTable 68:Function identificationIEC 61850 identification: ARCSARCIEC 60617 identification: ARCANSI/IEEE C37.2 device number: 50L/50NL5.4.2 FunctionalityThe arc protection (ARCSARC) detects arc situations in air insulated metal-cladswitchgears caused by, for example, human errors during maintenance or insulationbreakdown during operation.The function detects light from an arc either locally or via a remote light signal. Thefunction also monitors phase and residual currents to be able to make accuratedecisions on ongoing arcing situations.The function contains a blocking functionality. Blocking deactivates all outputs andresets timers.5.4.3 ApplicationThe arc protection can be realized as a stand-alone function in a single relay or as astation-wide arc protection, including several protection relays. If realized as astation-wide arc protection, different tripping schemes can be selected for theoperation of the circuit breakers of the incoming and outgoing feeders. Consequently,the relays in the station can, for example, be set to trip the circuit breaker of eitherthe incoming or the outgoing feeder, depending on the fault location in the switchgear.For maximum safety, the relays can be set to always trip both the circuit breaker ofthe incoming feeder and that of the outgoing feeder.The arc protection consists of:• Optional arc light detection hardware with automatic backlight compensation forlens type sensors• Light signal output FLT_ARC_DET for routing indication of locally detectedlight signal to another relay• Protection stage with phase- and earth-fault current measurement.The function detects light from an arc either locally or via a remote light signal.Locally, the light is detected by lens sensors connected to the inputs Light sensor 1,Light sensor 2, or Light sensor 3 on the serial communication module of the relay.Section 5 1MRS756378 DProtection functions162 REF615Application Manual
