A resistance temperature detector device and system are provided for measuring the temperature adjacent to windings within a stator assembly. The resistance temperature detector comprises a resistive element enclosed within a plurality of insulative layers, including insulation panels and adhesive. These surrounding insulation layers are sufficient to prevent partial discharge within any air gaps or low dielectric materials adjacent to the resistive element when the resistance temperature detector is disposed within a motor. A method for detecting temperatures between windings of an electrical machine is also provided.