Gas Driven Engine & Alternator Balancing
Vibration readings were taken on a generator driven engine and alternator at no-load and 100% load conditions. High vibration levels were observed, indicating an unbalance issue, which was resolved by adding correction weights.
This Report contains Vibration readings taken on Gan driven engine & alternator. Vibration measured in three mutually perpendicular directions i.e., in Horizontal Vertical and Axial direction and these readings were measured in No-Load & 100%load Condition. The overall value Velocity (RMS) and the frequency spectra’s over a bandwidth of 1 HZ to 1100 HZ were measured.
This generator was received in the workshop for a vibration test. The test was conducted at no load, and the vibration levels were found to be normal, below 1.5 mm/sec. However, when the generator was coupled with the engine at site, very high vibration levels were observed in all directions, with the maximum recorded on the generator NDE side in the vertical direction. The engine side vibration was also high, around 20 mm/sec.
Phase analysis was carried out, which indicated an unbalance issue, as the generator nde side phase angle (H–V) was found to be approximately 101.5°. Balancing was then performed by adding correction weights 300 gms on the DE side external fan. After balancing, the vibration levels were reduced from 28 mm/sec to 9.5 mm/sec, which is within the acceptable limit as per the relevant standard.