Motor faults usually have a specific pattern to recognize the fault occurrence, such as Line current frequency symptoms, duration, and amplitude variations. Those indices or patterns can reveal the fault type and its severity. The fault diagnosis process is expected to provide early information about the fault occurrence. This will assist the process of fault isolation, which in turn reduces its severity. In addition, this information will be helpful in the process of preventive maintenance for future planning. This book provides some useful information about fault modeling and diagnosis in line start PMSM.