2500 hp motor compressor case history

RCFA 2500 HP Motor/Compressor

#6 Air Compressor Motor AnalysisPrepared by: Bill Kilbey

bkilbey@gmail.comCell#: 865-776-9411

MIV Increase .18 to.45 in 20 minutes – due to soft foot binding or cocked bearing?

Sher - #6 Plant Air Compressor#6 AC -M2V Motor Inboard Vertical

Trend Display of Overall Value

-- Baseline -- Value: .183 Date: 01-May-15

0 0.004 0.008 0.012 0.016

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

Days: 01-May-15 To 01-May-15

PK V

eloci

ty in

In/S

ec

Date: Time: Ampl:

01-May-15 11:40:02 .453

MIV – Increase in 1xPK

Velo

city

in In

/Sec

Frequency in CPM

Sher - #6 Plant Air Compressor#6 AC -M2V Motor Inboard Vertical (01-May-15)

0 20000 40000 60000 80000

Max Amp .40

Plot Scale

0

0.5

11:21:1501-May-15

11:40:0301-May-15

11:40:2201-May-15

Freq: Ordr: Sp 3:

3600.1 1.008 .426

MIA – 3xTS may be cocked bearingSher - #6 Plant Air Compressor

#6 AC -M2A Motor Inboard AxialRoute Spectrum 01-May-15 11:21:37

OVERALL= .0406 V-DG PK = .0405 LOAD = 100.0 RPM = 3600. (59.99 Hz)

0 60 120 180 240 300

0

0.01

0.02

0.03

0.04

0.05

Frequency in kCPM

PK V

eloci

ty in

In/S

ec

Freq: Ordr: Spec:

3.666 1.018 .00803

Cross Channel Phase- 169 degrees axial 3/9 o’clock

169 Degrees- Cocked bearing

Problem Foot- corrected

Recommended Motor Inspection/Repair Plan• Remove motor to shop for test run uncoupled/unloaded 1 hour

• Record readings with spectrums every 10 minutes on both motor bearings vertical, horizontal and axial (Cascade Review)• Record bearing housing temperatures

• Disassemble motor• Inspect wear pattern in bearings- take digital pictures• Measure clearances of bearing bore to shaft and record• Measure motor end bracket housing clearance to bearing outside diameter with crush test (plasti-gauge or lead wire)

record clearance• Balance motor rotor with half key, then with half coupling and key used, measure and record shaft run-outs.

Provide balance report.• Reassemble motor, run on test stand one hour, record vibration and temperatures every 10 minutes (Cascade

Review)• Install motor with proper soft foot correction, run motor one hour uncoupled with half coupling.• Laser align and verify thermal offsets with FS• Run motor coupled/loaded and record vibration and temps on all bearings for 1 hour.

Wiped Motor Bearing