Our job was to find the cause of the vibration and eliminate it if possible.
FINDINGS: We started by identifying the frequency at which the chandelier was vibrating. We clocked the chandelier and identified the frequency to be 338 cycles per minute (CPM).
Next we collected data on the chandelier as the AHU, directly above was shut down. The vibration in the chandelier stopped, as expected. This meant that the chandelier vibration was directly related to the AHU.
We then proceeded to collect and analyze spectral vibration data from the AHU directly above the chandelier in question. We identified and labeled the spectrum with the mechanical vibrations (belts, fan and motor). (We would expect to see these mechanical vibrations in the data.) None of the mechanical vibration peaks matched the chandelier vibration of 338 CPM.
However, we did identify a peak that correlated with the chandelier vibration at 338 CPM. This meant that the problem vibration was not a mechanical issue, but instead was a Air Flow issue.
SOLUTION: Bring in an air flow specialist to correct the turbulence problem.
CONCLUSION: Although we were not able to eliminate this problem, we did identify it. Getting directly to the root cause of a problem not only saves time and money, but also can help keep you sane.
