Repair Report (DC Motor) - Fletcher Moorland...Repair Report (DC Motor) Customer Date Make Power...
Transcript of Repair Report (DC Motor) - Fletcher Moorland...Repair Report (DC Motor) Customer Date Make Power...
Repair Report (DC Motor)
Customer Date
Make
Power (Kw)
Frame
Speed (rpm)
Outgoing Photo
Order Number
Job No
Model
Voltage (v)
Winding
Current (A)
Mounting
Fletcher Moorland Ltd. Elenora Street, Stoke on Trent, ST4 1QGTel - 01782 411021 web - www.fletchermoorland.co.uk
Reported Faults / Customer Observations
Description
Nameplate
Rockwell Automation
12438101
500 v Arm, 300 v Field
Shunt
397 A, Arm, 18.83 A Field
Foot B3
Repeated failure of Drive End bearing 12 -13 months after servicing
EA 052903
250 Hp DC Motor
14 February 2010
Reliance
250 Hp
C4414 ATZ
850 / 2000
60481
Fletcher Moorland Ltd. Elenora Street, Stoke on Trent, ST4 1QGTel - 01782 411021 web - www.fletchermoorland.co.uk
Incoming Photo Stripdown report
Failure Photo Failure Analysis
Inspection / Test RunTest Run Conformance Check
CommentsHigh amplitude, high frequency vibration velocity and acceleration most noticeable at position 2 (drive end) of the motor. Expectation of drive end bearing damage.
The motor was relatively clean externally, internally there was evidence of carbon dust contamination. A foot was found to be broken on the resolver feedback module and a louvred brushgear cover was damaged. The NDE bearing was in good condition and the lubrication appeared clean. The DE bearing was rough to turn by hand and the lubrication appeared carburised. The NDE bearing housingwas oversize @ 170.035 mm.
The DE bearing was removed, cleaned and dismantled. It was evident from our failure analysis the bearing has suffered electrical current discharge damage. Further photos of the damaged bearing are shown later in this report.
Mechanical Fits & Data
Nominal mm
Up Tol
Lo Tol
Pass Fail
Shaft size
Keyway
Shaft run-out
Pass FailPass FailPass FailPass Fail
Pass Fail
Pass Fail
Pass Fail
Nominal size mm
Up Tol Lo Tol
Pass FailPass FailPass FailPass Fail
Nominal size
Up Tol Lo Tol
Pass FailPass FailPass FailPass Fail
Pass FailBearing Shoulder run-out
Journal Measurements - NDE
Nominal
Up Tol
Lo Tol
Journal Measurements - DE
mm
mm
Bearing Bearing
Fit Fit
8 Point Measurements 8 Point Measurements
8 Point Measurements 8 Point Measurements
Housing Measurements - NDE Housing Measurements - DEEEE
Pass FailBearing Shoulder run-out
Rotor Balance Data
Balance grade G1.0G1.0G1.0G1.0 G2.5G2.5G2.5G2.5
Plane
NDE
DE
Permitted (g) Actual (g) Position (Deg)
Foot Flatness
Motor viewed from above
Comments
Balance grade to ISO 1940/1 : 2003 Part 1
Total Indicated Run-out (TIR)
No of Bars
microns (um)
Commutator Profile TIR ReadingGood > 50 um
Satisfactory > 75 um
Fletcher Moorland Ltd. Elenora Street, Stoke on Trent, ST4 1QGTel - 01782 411021 web - www.fletchermoorland.co.uk
110
14.76
14.76
110.028 mm
110.012
110.012
110.012
110.012
110.012
110.012
2.99
10.80
232
52
110.010 mm
11
1620.00
0.00
0.00 0.05 0.05
0.05
0.00
0.00 0.00 0.00
0.00
0.00
NDE housing was oversize 170.035 mm on inspection.
110.012
95.015
95.015
95.012
95.015
95.015
95.015
95.012
95.015
95
95.018 mm
95.003 mm
3.6248 "
0.845 "
0.01 mm
170.020
170.020
170.020
170.020
170.020
170.020
170.020
170.020
170
170.025 170.000
200.015
200.015
200.015
200.015
200.015
200.015
200.015
200.015
200
200.028 200.000
110.012
6219 C3 6222 C3
Commutator Profile
Commutator Profile (Blue trace - as received, Red trace - after machining)
Fletcher Moorland Ltd. Elenora Street, Stoke on Trent, ST4 1QGTel - 01782 411021 web - www.fletchermoorland.co.uk
Electrical Data - Static Test
Winding Resistance
Fletcher Moorland Ltd. Elenora Street, Stoke on Trent, ST4 1QGTel - 01782 411021 web - www.fletchermoorland.co.uk
Insulation Resistance (IR) V@
Electrical Data - Run TestNo load test
V Voltage - Armature
rpm (CW)Motor Speed
ACurrent - Armature
ACurrent - Fields
Load test
KwMeasured Output Power
Earth leakage V@uA
Ohms
MOhm
Winding Resistance
Insulation Resistance (IR)
V@
Earth leakage V@uA
Ohms
MOhm
V Voltage - Fields
rpm (CCW)Motor Speed
V Voltage - Armature
rpm Motor Speed
ACurrent - Armature
ACurrent - Fields
V Voltage - Fields
Field Circuit Armature Circuit
NmMeasured Output Torque
Repair Details / Service Report
1800
50
1486
The motor was fully stripped down and all mechanical parts were checked for correct fit and tolerance. The NDE bearing housing was found to be oversize 170.035 mm (Tolerance 170.025mm - 170.000mm)The housing was bored, sleeved and machined to 170.020 mm. All mechanical parts were blast cleaned and all interior surfaces were spray painted with an anti-track paint. The windings were cleanedand checked for integrity. All winding temperature control devices were checked for correct function.Thecommutator was profiled before being skimmed, undercut and chamfered. A finished profile was recorded. The armature was dual plane dynamically balanced to an enhanced G1.0 balance grade for low vibration operation. The resolver feedback module was checked for correct function and outputs (2,2v pk vector, 2,2v pk SIN, 2,2 vpk COS) Mechanical repairs were carried out to the resolver foot and louvred brushgear panels. A genuine SKF insulated bearing was fitted to the NDE of the motor (6219 C3 VL0241) A SKF 6222 C3 was fitted to the DE.
The motor was assembled and 16 pairs of new brushed were fitted and bedded in.
The motor was run on our test bed and SKF conformance check results were taken and recorded.
The motor was spray painted and packaged ready for delivery.
999 500
356
1485
15.1
14.6
4.3
3.42 1800
0.013 - 0.014
999 500
7.62
Mechanical Conformance Check Data & Vibration Analysis
Conformance Check
Fletcher Moorland Ltd. Elenora Street, Stoke on Trent, ST4 1QGTel - 01782 411021 web - www.fletchermoorland.co.uk
Vibration Analysis
CommentsThe final test run show the motor has passed the SKF conformance check. Compared to the initial testrun all vibration levels are within limits for each band.
This motor has been fitted with an insulated bearing fitted on the NDE of the motor. Do not allow any ground connection to be made to this bearing by fitting temperature sensing or other metallic conductors.
Fletcher Moorland Ltd. Elenora Street, Stoke on Trent, ST4 1QGTel - 01782 411021 web - www.fletchermoorland.co.uk
Photo Description
Photo Description
Photo Description
Further Analysis / Information
Frosting evident on the inner raceway of the bearing.
fluting evident on the outer raceway of the bearing.
Evidence of carbonisation of lubricant as found on stripdown, note the fresh lubricant evident on the outer race of the bearing. (this has not entered the bearing and has not been subjected to electrical current discharge.