Detection of Rooftop Cooling Unit Faults Based on Electrical Measurements

Nonintrusive load monitoring (NILM) is accomplished by sampling voltage and current at high rates and reducing the resulting start transients or harmonic contents to concise “signatures.” Changes in these signatures can be used to detect, and in many cases directly diagnose, equipment and component faults associated with rooftop cooling units. Use of the NILM for fault detection and diagnosis (FDD) is important because (1) it complements other FDD schemes that are based on thermo-fluid sensors and analyses and (2) it is minimally intrusive (one measuring point in the relatively protected confines of the control panel) and therefore inherently reliable. This paper describes changes in the power signatures of fans and compressors that were found, experimentally and theoretically, to be useful for fault detection.

[1]  Peter Ross Armstrong.  Model identification with application to building control and fault detection , 2004 .

[2]  Werner Soedel,et al.  An Investigation of Compressor Slugging Problems , 1994 .

[3]  M. Mackisack.  Chance Encounters: A First Course in Data Analysis and Inference , 2001 .

[4]  Steven R. Shaw,et al.  A Kalman-Filter Spectral Envelope Preprocessor , 2007, IEEE Transactions on Instrumentation and Measurement.

[5]  Steven B. Leeb,et al.  A conjoint pattern recognition approach to nonintrusive load monitoring , 1993 .

[6]  Steven B. Leeb,et al.  Power signature analysis , 2003 .

[7]  Kwangduk Douglas Lee,et al.  Electric load information system based on non-intrusive power monitoring , 2003 .

[8]  James E. Braun,et al.  Common faults and their impacts for rooftop air conditioners , 1998 .

[9]  Todd M. Rossi,et al.  A Statistical, Rule-Based Fault Detection and Diagnostic Method for Vapor Compression Air Conditioners , 1997 .

[10]  G. W. Hart,et al.  Nonintrusive appliance load monitoring , 1992, Proc. IEEE.

[11]  James E. Braun,et al.  Evaluating the Performance of a Fault Detection and Diagnostic System for Vapor Compression Equipment , 1998 .

[12]  Steven B. Leeb,et al.  Instrumentation for High Performance Nonintrusive Electrical Load Monitoring , 1998 .

[13]  Lennart Ljung,et al.  System Identification: Theory for the User , 1987 .

[14]  Giancarlo Genta,et al.  Vibration of Structures and Machines: Practical Aspects , 1992 .

[15]  Chris J. Wild,et al.  Chance Encounters: A First Course in Data Analysis and Inference Reviewed by Flavia Jolliffe , 1999 .

[16]  James E. Braun,et al.  An Economic Evaluation of Automated Fault Detection and Diagnosis for Rooftop Air Conditioners , 2004 .

[17]  C. Wunsch.  The Ocean Circulation Inverse Problem , 1996 .