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Hey all,
I am now troubleshooting on RR Allison 501-KB7 (Gas Turbine Generator Set) package after new engine change-out.
When unit successfully start-up with no load and in stable at @242.81Hz/14570 RPM, vibration high at #3 bearing which is the spectrum shows fluctuated subsynchronous peaks (7, 14, 24hz @ 20-30 micron pk-pk) while the shaft frequency maintain in low value (242.81Hz @ 12-13 micron pk-pk).
After unit successfully load, most of the subsynchronous peaks suddenly reduced to below 7 micron pk-pk and just a peak suddenly high and maintained the amplitude at 24.98Hz/1498RPM/0.102X turbine (same frequency of output gearbox/alternator). Amplitude value higher than 1X turbine shaft recorded 36 micron pk-pk while 1X turbine amplitude is 13micron pk-pk.
The questions are:
1) What is the possible problem to this situation that caused of high vibration. Previous engine recorded maintain in 16-18 micron pk-pk during load.
2) Is it possible the problem related to gearbox/alternator since the frequency is the same? Transmitted vibration? While the alternator vibration reading high at 43-45 micron pk-pk (same range with previous engine).
Hope will get some input from you guys according to this issue.
Thanks.
I am now troubleshooting on RR Allison 501-KB7 (Gas Turbine Generator Set) package after new engine change-out.
When unit successfully start-up with no load and in stable at @242.81Hz/14570 RPM, vibration high at #3 bearing which is the spectrum shows fluctuated subsynchronous peaks (7, 14, 24hz @ 20-30 micron pk-pk) while the shaft frequency maintain in low value (242.81Hz @ 12-13 micron pk-pk).
After unit successfully load, most of the subsynchronous peaks suddenly reduced to below 7 micron pk-pk and just a peak suddenly high and maintained the amplitude at 24.98Hz/1498RPM/0.102X turbine (same frequency of output gearbox/alternator). Amplitude value higher than 1X turbine shaft recorded 36 micron pk-pk while 1X turbine amplitude is 13micron pk-pk.
The questions are:
1) What is the possible problem to this situation that caused of high vibration. Previous engine recorded maintain in 16-18 micron pk-pk during load.
2) Is it possible the problem related to gearbox/alternator since the frequency is the same? Transmitted vibration? While the alternator vibration reading high at 43-45 micron pk-pk (same range with previous engine).
Hope will get some input from you guys according to this issue.
Thanks.
