Fault Detection and Diagnostics for Rooftop Air Conditioners

Figure 4-17 Outputs of the FDD demonstration after introduction of liquid line restriction
fault ........................................................................................................................... 70
Figure 4-18 Outputs of the FDD demonstration after introduction of compressor leakage
fault ........................................................................................................................... 71
Figure 4-19 Outputs of the FDD demonstration after removal of condenser fouling fault
................................................................................................................................... 72
Figure 4-20 Outputs of the FDD demonstration after removal of liquid line restriction
fault ........................................................................................................................... 73
Figure 4-21 Outputs of the FDD demonstration after removal of compressor leakage fault
................................................................................................................................... 74
Figure 4-22 Outputs of the FDD demonstration after removal of low refrigerant low
charge fault................................................................................................................ 75
Figure 4-23 Histogram bar plot of the normalized fault indicator for liquid line restriction
................................................................................................................................... 77
Figure 4-24 Histogram bar plot of the normalized fault indicator for refrigerant low
charge........................................................................................................................ 77
Figure 4-25 Histogram bar plot of the normalized fault indicator for condenser fouling 78
Figure 4-26 Histogram bar plot of the normalized fault indicator for compressor valve
leakage ...................................................................................................................... 79
Figure 4-27 Histogram bar plot of the normalized fault indicator for cooling capacity
degradation................................................................................................................ 80
Figure 4-28 Histogram bar plot of the return air temperature .......................................... 80
Figure 4-29 Histogram bar plot of the continuous running time between off-cycles of the
RTU........................................................................................................................... 81
Figure 4-30 Histogram bar plot of the normalized fault indicator for EER degradation.. 82
Figure 4-31 System power consumption reduction .......................................................... 82
Figure 5-1 Interrelationship among different factors affecting RTU performance .......... 88
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