One of the less common but more ‘popular’ defects in electrical and current signature analysis.
Motor Information: 1 hp, 1765 rpm, 460 Vac, 60 Hz, across the line. 28 rotor bars and 36 stator slots.
Hint: pole pass frequency is 2x slip frequency or the number of poles times slip. When rotor faults are significant then there may also be dynamic eccentricity.
Low frequency data (180 Hz) 12kHz sampling, 65536 FFT block, 9 seconds, 0.022 Hz bin size.
High frequency data, 0.11 Hz bin size. FMAX is 6kHz, but limited to 1500 Hz for this purpose.