Field case · Condition monitoring
FD fan: phase and motion amplification showed a loose pedestal, saving a rotor replacement
Quick answer
A forced-draught fan had chronic vibration, and the plant was considering a new rotor. The spectrum had harmonics but the time waveform had no impacts. Phase analysis and motion amplification showed the non-drive-end pedestal moving. Bolting and fixing it dropped axial vibration from 8.3 to 1.8 mm/s RMS.
What the case covers
- The symptom
- Part 1: the readings
- Part 2: phase, then motion amplification
- The fix and the result
- What to take from it
Takeaway. Before replacing a rotor for chronic vibration, check the support. Phase and motion amplification found a loose pedestal and saved the rotor.
Read the full case, with the data and the numbers