Patent Number: 054854911
Section: abstract

An online system for diagnosing operability of a rotating electrical apparatus includes sensors producing electrical variables corresponding to operating conditions of the apparatus, data converters for converting the electrical variables to digital values, a comparator for comparing the values to corresponding predetermined baseline values of the apparatus and producing a corresponding comparison value, and a signalling mechanism for outputting signals related to a period of predicted operability of the apparatus whenever the comparison value exceeds a corresponding predetermined deadband value. The operating conditions may be non-electrical operating conditions, such as a condition of a lubrication system or a bearing of the apparatus. Alternatively, the sensors may sense electrical insulation non-thermal parameters during operation of the apparatus, in order to produce signals related to the operability of an insulator of the apparatus. The system may have a local processor for performing the comparisons and signaling. Alternatively, the system may include an intermediate data storage and communication mechanism for storing and communicating the sensed values to a remote processor. The processor may also trend the values with respect to time and determine a derivative of a sensed value. The apparatus may be a motor operating in a hazardous environment, such as a reactor coolant pump (RCP) motor operating in a nuclear containment vessel.