Continuation Sheet Edison Electrical Works Page 2 of 2
Motor : ABB make, 6.6 KV, 2611 KW, 1492 RPM Cage Induction Motor
Load : 3 stage centrifugal compressor via a gear box and intermediate coupling & two flex-packs of 16 mm
Thick on either side of intermediate coupling.
Vibration Levels at about 1490 RPM (Motor in Coupled Condition)
Pickup / Overall /Frequency spectrum
Peak Velocity in mm/sec / Peak Velocity in mm/sec/ RPM / Peak Velocity mm/sec
/ RPM / Peak Velocity mm/sec
/ RPM / Peak Velocity mm/sec
/ RPM / Peak Velocity mm/sec
/ RPM
Point / Axis
DE / H / 1.70 / 1.15 / 1500 / 0.07 / 3000 / 0.05 / 4500 / 0.62 / 5850 / 0.05 / 7350
V / 1.01 / 0.19 / 1500 / 0.14 / 3000 / 0.27 / 4500 / 0.54 / 6000 / 0.04 / 7350
A / 4.49 / 0.89 / 1500 / 0.52 / 3000 / 0.17 / 4500 / 0.09 / 5100 / 3.24 / 5850
ODE / H / 4.11 / 3.19 / 1500 / 0.06 / 3000 / 0.04 / 3600 / 0.09 / 4350 / 0.02 / 5400
V / 2.66 / 0.87 / 1500 / 0.14 / 3000 / 0.09 / 4500 / 1.84 / 5850 / 0.02 / 6750
A / 8.42 / 0.92 / 1500 / 0.32 / 3000 / 0.01 / 3600 / 0.16 / 4350 / 6.48 / 5850
Vibration Levels at about 1490 RPM (Motor in De-Coupled Condition)
Pickup / Overall /Frequency spectrum
Peak Velocity in mm/sec / Peak Velocity in mm/sec/ RPM / Peak Velocity mm/sec
/ RPM / Peak Velocity mm/sec
/ RPM / Peak Velocity mm/sec
/ RPM / Peak Velocity mm/sec
/ RPM
Point / Axis
DE / H / 0.68 / 0.38 / 1500 / 0.02 / 3000 / 0.02 / 4500 / 0.34 / 5850 / 0.03 / 7350
V / 1.11 / 0.23 / 1500 / 0.16 / 3000 / 0.02 / 4350 / 0.81 / 5850 / 0.03 / 7350
A / 3.71 / 0.35 / 1500 / 0.33 / 3000 / 0.02 / 4350 / 0.03 / 4800 / 2.87 / 5850
ODE / H / 1.25 / 0.93 / 1500 / 0.11 / 3000 / 0.03 / 4350 / 0.28 / 5850 / 0.01 / 7350
V / 1.58 / 0.29 / 1500 / 0.09 / 3000 / 0.01 / 4500 / 1.22 / 5850 / 0.03 / 7350
A / 7.57 / 0.34 / 1500 / 0.23 / 3000 / 0.01 / 3750 / 0.01 / 4500 / 5.98 / 5850
Vibration Measuring Equipment : VMI AB (Sweden) make, Easy Balancer
NOTE :
1. The axial vibration (rms) in ODE goes up when the supply frequency goes down and vice versa, when running on load, as below.
9.4 mm/sec at 48.2 Hz
7.5 mm/sec at 48.8 Hz
6.5 mm/sec at 49.0 Hz
4.8 mm/sec at 49.5 Hz
3.5 mm/sec at 50.1 Hz
2. In decoupled condition, the peak vibration velocity dropped from 7.5 mm/sec to about 1 mm/sec within 2
seconds of switching off the power supply.