17.10.3 Setting guidelines GUID-D3BED56A-BA80-486F-B2A8-E47F7AC63468 v1The settings tAlarm and tWarning are user settable limits defined in hours. Theachievable resolution of the settings is 0.1 hours (6 minutes).tAlarm and tWarning are independent settings, that is, there is no checkif tAlarm > tWarning.The limit for the overflow supervision is fixed at 99999.9 hours.The setting tAddToTime is a user settable time parameter in hours.17.11 Estimation of transformer insulation life LOLSPTR(26/49HS) GUID-D9D1F036-EC75-40A8-860F-192CF1F6F759 v1GUID-A3D72F4B-9567-4DF0-867A-9F657A7E9291 v1Function description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberEstimation of transformer windinginsulation lifeLOLSPTR3Ihp>T 26/49HS17.11.1 Application GUID-7F37B3D6-C98E-4780-AB5B-12780566FFA2 v1A typical power transformer is composed of:• Laminated steel core with copper or aluminium windings• Solid refined paper insulation• Highly refined mineral oil as insulating and cooling medium for the entiretransformerThe oil is cooled by a separate cooling system using air or water. The core, windingsand insulation have specific thermal capabilities.Losses in the winding and core can cause temperature rises in the transformer, which istransferred to the insulating oil. Failure to limit these temperature rises to the thermalcapability of the insulation and core materials can cause premature failure of thetransformer.A transformer is rated at the power output. It can continuously deliver at rated voltageand frequency without exceeding the specified temperature limit. This temperature riseis based on thermal limitations of the core, winding and insulation. Therefore,1MRK 511 401-UUS A Section 17MonitoringBay control REC670 2.2 ANSI 545Application manual
