Old Dominion University ODU Digital Commons Engineering Management & Systems Engineering Management & Systems Engineering Theses & Dissertations Engineering Fall 2017 Emergency Diesel-Electric Generator Set Maintenance and Test Periodicity Stephen John Fehr Old Dominion University, [email protected] Follow this and additional works at: https://digitalcommons.odu.edu/emse_etds Part of the Operational Research Commons, and the Statistics and Probability Commons Recommended Citation Fehr, Stephen J.. "Emergency Diesel-Electric Generator Set Maintenance and Test Periodicity" (2017). Doctor of Philosophy (PhD), Dissertation, Engineering Management & Systems Engineering, Old Dominion University, DOI: 10.25777/q2nk-n411 https://digitalcommons.odu.edu/emse_etds/24 This Dissertation is brought to you for free and open access by the Engineering Management & Systems Engineering at ODU Digital Commons. It has been accepted for inclusion in Engineering Management & Systems Engineering Theses & Dissertations by an authorized administrator of ODU Digital Commons. For more information, please contact [email protected]. EMERGENCY DIESEL-ELECTRIC GENERATOR SET MAINTENANCE AND TEST PERIODICITY by Stephen John Fehr M.S. December 2014, Old Dominion University B.S. December 1997, Pennsylvania State University A Dissertation Submitted to the Faculty of Old Dominion University in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY ENGINEERING MANAGEMENT AND SYSTEMS ENGINEERING OLD DOMINION UNIVERSITY November 2017 Approved by: T. Steven Cotter (Director) Holly Handley (Member) Jennifer Michaeli (Member) Cesar Pinto (Member) Resit Unal (Member) ABSTRACT EMERGENCY DIESEL-ELECTRIC GENERATOR SET MAINTENANCE AND TEST PERIODICITY Stephen John Fehr Old Dominion University, 2017 Director: Dr. T. Steven Cotter Manufacturer and industry recommendations vary considerably for maintenance and tests of emergency diesel-electric generator sets in emergency standby duty. There is little consistency among generator sets of similar technology, and manufacturers and their representatives often provide contradictory guidance. As a result, periodicity of emergency diesel-electric generator set maintenance and tests varies considerably in practice. Utilizing the framework proposed and tested by Fehr (2014), this research developed a parametric regression survival model of the reliability of modern diesel-electric generator sets in emergency standby duty as a function of maintenance, age, and cumulative run hours. A survival regression technique leveraging Cox’s (1972) methods was developed to combine multiple exponential and Weibull (1951) distributions into a single model to represent emergency diesel-electric generator sets and other complex machinery exhibiting multiple independent failure distributions. A generalized model and reliability tables derived from that model are presented along with maintenance and test recommendations to assist managers in determining the optimal maintenance program for a diesel-electric generator set. iii Copyright, 2017, by Stephen J. Fehr, All Rights Reserved. iv TABLE OF CONTENTS Page LIST OF TABLES .................................................................................................................... vi LIST OF FIGURES ................................................................................................................. vii Chapter I. INTRODUCTION ..................................................................................................................1 PURPOSE ....................................................................................................................... 2 RESEARCH QUESTIONS AND HYPOTHESES........................................................... 3 SYSTEM COMPONENTS............................................................................................ 10 MAINTENANCE.......................................................................................................... 12 TESTS .......................................................................................................................... 13 GENERATOR SET RATINGS ..................................................................................... 15 II. LITERATURE REVIEW .................................................................................................... 17 HISTORICAL EMERGENCY DIESEL-ELECTRIC GENERATOR RESEARCH ....... 20 DIESEL ENGINE MAINTENANCE RESEARCH IN OTHER APPLICATIONS ........ 22 RARE EVENTS SURVIVAL ANALYSIS ................................................................... 25 ANALYSIS METHODS IN RELATED FIELDS .......................................................... 26 POST-HOC POWER ANALYSIS AND VALIDITY .................................................... 30 SECONDARY DATA ................................................................................................... 36 III. METHODOLOGY ............................................................................................................. 41 RESEARCH SCOPE ..................................................................................................... 44 RELIABILITY PREDICTORS ..................................................................................... 48 DATA ACQUISITION ................................................................................................. 51 DATA REQUIRED ....................................................................................................... 53 NEW COX/WEIBULL REGRESSION TECHNIQUE .................................................. 56 DELIMINATIONS AND ASSUMPTIONS .................................................................. 62 IV. ANALYSIS........................................................................................................................ 64 DATA ........................................................................................................................... 64 INITIAL ANALYSIS .................................................................................................... 67 COX REGRESSION ANALYSIS RESULTS ............................................................... 70 PARAMETRIC REGRESSION ANALYSIS, FULL MODEL ...................................... 76 PARAMETRIC REGRESSION ANALYSIS, SIMPLIFIED MODEL ........................... 84 V. RESULTS AND DISCUSSION .......................................................................................... 88 HYPOTHESIS TESTS RESULTS ................................................................................ 90 DISCUSSION ............................................................................................................. 101 GENERALIZABILITY ............................................................................................... 108 v Page LIMITATIONS ........................................................................................................... 110 AVAILABILITY CALCULATIONS .......................................................................... 112 OTHER APPLICATIONS ........................................................................................... 113 VI. CONCLUSIONS .............................................................................................................. 116 RECOMMENDATIONS ............................................................................................. 119 BIBLIOGRAPHY ................................................................................................................... 124 APPENDICES ........................................................................................................................ 132 A.SURVEY FORM ..................................................................................................... 132 B.REGRESSION OUTPUT ........................................................................................ 135 C.RELIABILITY TABLES ......................................................................................... 158 D.NFPA 110 (2016) RECOMMENDATIONS ............................................................ 160 VITA ...................................................................................................................................... 161 vi LIST OF TABLES Table Page Table 1. Table of Predictor, Data and Variable Descriptions ........................................................8 Table 2. Cummins Power Generator Recommended Maintenance (Loehlein, 2007) .................. 19 Table 3. Equipment Failure Rate Multipliers vs. Maintenance Quality (IEEE 493-2007) ........... 24 Table 4. Table of Test and Maintenance Actions ....................................................................... 50 Table 5. Table of Test and Maintenance Action Periodicity ....................................................... 51 Table 6. Table of Predictor Significance When Added to or Replacing a Potentially Conflated Predictor in the Model of Equation 11. ...................................................................................... 75 Table 7. Hypothesis Test Results Summary ............................................................................... 91 Table 8. Model Parameter Calculations From the Spreadsheet Regression for x16 ≤ 1. ............. 153 Table 9. Model Parameter Calculations From the Spreadsheet Regression for x16 =7. .............. 154 Table 10. Emergency Diesel-Electric Generator Set Typical Reliability Table for 31.2 Annual Run Hours ..............................................................................................................................