Set the IDLDPU with a sufficient margin below the minimum expected load current. Asafety margin of at least 15-20% is recommended. The operate value must howeverexceed the maximum charging current of an overhead line, when only one phase isdisconnected (mutual coupling to the other phases).Set the VDLDPU with a sufficient margin below the minimum expected operatingvoltage. A safety margin of at least 15% is recommended.14.3 Fuse failure supervision VDSPVC (60) GUID-9C5BA1A7-DF2F-49D4-A13A-C6B483DDFCDC v214.3.1 Identification GUID-109434B0-23E5-4053-9E6E-418530A07F9C v2Function description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberFuse failure supervision VDSPVC VTS 6014.3.2 Application GUID-AD63BF6C-0351-4E48-9FB2-9AB5CF0C521E v2Some protection functions operate on the basis of measured voltage at the relay point.Examples of such protection functions are distance protection function, undervoltagefunction and energisation-check function. These functions might mal-operate if there isan incorrect measured voltage due to fuse failure or other kind of faults in voltagemeasurement circuit.VDSPVC is designed to detect fuse failures or faults in voltage measurement circuitbased on comparison of the voltages of the main and pilot fused circuits phase wise.VDSPVC output can be configured to block voltage dependent protection functionssuch as high-speed distance protection, undervoltage relays, underimpedance relaysand so on.1MRK 504 163-UUS A Section 14Secondary system supervisionTransformer protection RET670 2.2 ANSI 673Application manual
