SeqTypeIPol: It is used to select type of current polarization quantity, i.e. ZeroSeq andNegSeq for direction detection.SeqTypeIDir: It is used to select type of operating quantity, i.e. ZeroSeq and NegSeq fordirection detection.Operation: Sets the protection to Enabled or Disabled.EnaDir: Enables the directional calculation in addition to the directional mode selectionin each step.7.6.3.1 Settings for steps 1 and 4n means step 1 and 4. x means step 1, 2, 3 and 4.DirModeSelx: The directional mode of step x. Possible settings are Disabled/Non-directional/Forward/Reverse.Characteristn: Selection of time characteristic for step n. Definite time delay and differenttypes of inverse time characteristics are available.Inverse time characteristic enables fast fault clearance of high current faults at the sametime as selectivity to other inverse time phase overcurrent protections can be assured. Thisis mainly used in radial fed networks but can also be used in meshed networks. In meshednetworks the settings must be based on network fault calculations.To assure selectivity between different protections, in the radial network, there have to bea minimum time difference Dt between the time delays of two protections. The minimumtime difference can be determined for different cases. To determine the shortest possibletime difference, the operation time of protections, breaker opening time and protectionresetting time must be known. These time delays can vary significantly between differentprotective equipment. The following time delays can be estimated:Protection operate time: 15-60 msProtection resetting time: 15-60 msBreaker opening time: 20-120 msThe different characteristics are described in the Technical Manual (TM).tx: Definite time delay for step x. The definite time tx is added to the inverse time wheninverse time characteristic is selected.Pickup"x": Operate residual current level for step x given in % of IBase.1MRK 506 334-UUS A Section 7Current protection205Application manual
