Once again I am coming here with similar kind of machine and vibration problem.
EMD engine with an Alternator (with single bearing at NDE)
RPM : 900 RPM
Alternator: 600V, 2525KVA, 1400kw, 60 HZ
- Engine vibrations are within range (around 8-9 mm/s)
- Alternator NDE is vibrating with High vertical (24 mm/s , purely 1X)
- & Axial (16 mm/s with 1X = 8.6, max peak 12 mm/s @7182 cpm and minor 2X,3X, 4X) vibrations.
(due connectivity issue at offshore I counldn't upload the spectrum here. Will upload soon once I reach onshore.)
- vibration velocity (mm/s, RMS) with phase:
V H A
Alt DE 5.4@ 170 5.7@ 86 16@ 8
Alt NDE 24@ 15 4.1@ 140 16@190
I have also taken phase readings at NDE axial plane. (attached.)
I am still fighting with an issue.
- Done with laser-alignment with all readings ≤ 0.04 mm (within tolerance)
- foundation base frame checked & found ok.
- Started with balacing trial and will come with conclusion by tomorrow.
Please suggest guys.