On-line stator temperature monitor for single-phase induction motors

Abstract

All electrical appliances containing electric motors sold in Australia must comply with the relevant stator winding temperature rise specification in IEC Standard IEC 60335.1. The temperature rise is commonly estimated based on the change in the DC resistance of the stator winding before and after the operating test. This method is accurate and widely used but does not allow continuous monitoring of the winding temperature during the test. This paper describes the design, construction and preliminary testing of a monitoring device which allows continuous on-line temperature measurement of single-phase AC induction motors with a direct readout of temperature.