Patent ID: 6086249
Filing Date: 2000-07-11
Classification: G01K

Abstract:
A method for reproducing and displaying the winding temperature of an electric power transformer using a thermometer system comprising a hollow sensor element, a mechanical transducer connected though a capillary tube with sensor element to actuate a mechanical display including at least one switch, said sensor element, capillary tube and transducer together forming a closed pressure chamber filled with a test medium having a pressure which changes in relation to temperature, comprising the steps of:providing a heating chamber separate from and spaced apart from a container for the power transformer,immersing an electric heater in the test medium in the separate heating chamber,measuring the temperature of a coolant cooling the power transformer by directly positioning the sensor element in the coolant and ascertaining a pressure produced in the transducer,correcting the measured temperature by the electric heater fed with a current proportional to the load of the power transformer, wherein additional pressure corresponding to the winding temperature of the power transformer is produced, in a step separate from the direct measuring of transformer coolant temperature via the sensor element, by directly heating the test medium by the electric heater in said test medium andascertaining and displaying the temperature by the total pressure of the test medium in the transducer.