Fiber optic temperature sensors are now routinely installed into large motor and power generator equipment to provide real-time monitoring and thermal protection of critical stator windings and bearing hot spots.

The safe operating temperature of rotating machine windings is limited by the heat which the insulating material can stand before eventual deterioration. This temperature and deterioration rate varies with different classes of insulating materials. Insulation deterioration at a given temperature is approximately proportional to the length of time that the temperature is above the critical threshold. Until recently, RTD’s (resistance temperature detectors) were typically embedded into windings to provide continuous monitoring, despite the inaccuracies caused by EMI/RFI interference. Now, OSENSA’s innovative technology has enabled the deployment of low-cost fiber optic temperature sensors.