In an intertrip scheme, the send signal is initiated by an underreaching zone or froman external protection (transformer or reactor protection). At the remote end, thereceived signals initiate a trip without any further protection criteria. To limit therisk for an unwanted trip due to the spurious sending of signals, the timer tCoordshould be set to 10-30 ms dependant on the type of communication channel.The general requirement for teleprotection equipment operating in intertrippingapplications is that it should be very secure and very dependable, since bothinadequate security and dependability may cause unwanted operation. In someapplications the equipment shall be able to receive while transmitting, andcommands may be transmitted over longer time period than for other teleprotectionsystems.16.1.3 Setting guidelines IP15021-1 v1M13869-4 v4The parameters for the scheme communication logic function are set via the localHMI or PCM600.Configure the zones used for the CS send and for scheme communication trippingby using the ACT configuration tool.The recommended settings of tCoord timer are based on maximal recommendedtransmission time for analogue channels according to IEC 60834-1. It isrecommended to coordinate the proposed settings with actual performance for theteleprotection equipment to get optimized settings.16.1.3.1 Blocking scheme M13869-8 v6SetOperation =OnSetSchemeType =BlockingSettCoord = 25 ms (10 ms + maximal transmission time)SettSendMin = 0 sSetUnblock =Off(Set toNoRestart if Unblocking scheme with no alarm for loss of guard is to beused.Set toRestart if Unblocking scheme with alarm for loss of guard is to be used)SettSecurity = 0.035 s16.1.3.2 Delta blocking scheme GUID-F4359690-F433-46CB-A173-8C14559E3FCF v1SetOperation =OnSetSchemeType =DeltaBlockingSettCoord = 0 sSettSendMin = 0 sTable continues on next page1MRK 506 369-UEN B Section 16Scheme communicationLine distance protection REL670 2.2 IEC 707Application manual
