Identifying VFD Electrical Fluting
IVC Technologies
Jay Keith
Introduction
• In today’s industry the use of variable speed
machinery has increased in popularity to reduce
cost such as to enhance energy efficiency.
Problem diagnostics and trouble shooting of
these machines can be very time consuming. A
major problem with variable speed machines is
electrical fluting. Electrical fluting can be quickly
detected by vibration monitoring if the proper
diagnostic techniques are used.
Cascade Line 9 Winder
CONV - LINE 9 WINDER MOTOR
L9WINDMTR -M2H MOTOR INBOARD HORIZONTAL
65 ORDERS
.39
-.31
Acceleration in G-s
09-Feb-09 10:30
100 ORDERS
4.35
-4.46
09-Feb-09 10:31
0
0.3
0.6
Time in Seconds
0.9
• As seen peak vue indicates an outer race defect fault of
1.2
the outboard motor bearing. But in the velocity spectrum
at 65 orders there is very little amplitude and energy in
the waveform. Data taken at 100 orders indicted a high
frequency vibration with high impacting. This is due to
electrical fluting which causes excessive wash boarding
of the bearing outer or inner race. The problem and
severity are only indicated in peak vue and velocity at
100 orders.
American Gypsum Stucco Fan
all - STUCCO COOLER SYSTEM FAN
2_3_24FAN -M1H MOTOR OUTBOARD HORIZONTAL
100 ORDERS
15.3
-16.3
Acceleration in G-s
08-Jul-09 14:08
65 ORDERS
4.72
-5.00
08-Jul-09 14:07
0
50
100
150
200
Time in mSecs
250
300
350
• As seen peak vue indicates an outer race defect fault of
400
the outboard motor bearing. But in the velocity spectrum
at 65 orders there is very little amplitude and energy in
the waveform. Data taken at 100 orders indicted a high
frequency vibration with high impacting. This is due to
electrical fluting which causes excessive wash boarding
of the bearing outer or inner race. The problem and
severity are only indicated in peak vue and velocity at
100 orders.
Palmetto Health VFD Pump #1
EF - CHILLED WATER VFD PUMP #1
18201 -MIV MOTOR OUTBOARD VERTICAL
100 ORDERS
22.9
-22.6
Acceleration in G-s
26-Oct-09 12:05
65 ORDERS
2.22
-1.94
26-Oct-09 12:04
0
100
200
300
400
Time in mSecs
500
600
700
• As seen peak vue indicates an outer race defect fault of
800
the outboard motor bearing. But in the velocity spectrum
at 65 orders there is very little amplitude and energy in
the waveform. Data taken at 100 orders indicted a high
frequency vibration with high impacting. This is due to
electrical fluting which causes excessive wash boarding
of the bearing outer or inner race. The problem and
severity are only indicated in peak vue and velocity at
100 orders.
Conclusion
• On numerous occasions variable speed machinery data has
indicated a bearing fault in peak vue with very little indication of
wear in velocity at 65 orders. But when velocity at 100 orders is
acquired, the severity of the fault is indicated. This is an indication
of electrical fluting. Electrical fluting is indicated at a higher
frequency range due to the excessive wash boarding of the bearing
outer or inner race. So to quickly and properly identify bearing faults
of variable frequency drives, velocity data should be taken at 100
orders with 3200 lines and 4 averages along with peak vue at 40
orders with 1600 lines and 2 averages.