Tagged With "Motor"

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5MW 3phase motor, Single phase overload trip

Lampard Nguyen ·
Dear Experts, We have 6.6KV wound rotor motor, 5MW, 500A FLA, cement milling motor. For 2 years operating, about 1 month to 2 months operating, motor is trip by single phase overload (always random 2 phase ~ 450A, 1 phase ~ 1000A).  We have...
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6000 v elecric motor high vibration

aziz58 ·
dear all i am facing with high voltage vertical electric motor as follow pole:6 out put:1250kw frequency:50hz speed:993 voltage;6000 v we have high vibration about 5.5 mm/s at 100 HZ de side.but at nde side vibration is 1mm/s. free run test was as same.phase measurement is fluctuated around the body and base.we mount the motor on the same another foundation but vibration was still exist .we decide run the motor on wokeshop on the ground and we put wood block under motor.we tun motor at...
Blog Post

VFD Security Risk

Reliability ·
Vendors include this setting intentionally in the device’s registry so operators will always know the top speed-limit for motors. But the devices reveal this critical speed to anyone who queries them. They use the Modbus protocol to communicate, and a hacker can send a simple query to the drive’s control board to obtain this critical information then use it against the device.
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2100 KW motor high vibration

Velmurugan ·
I am facing high vibration in motor non drive & drive bearing in all three directions (H,V,A). please see the readings below Motor non drive bearing H-6.12 mm/sec, V-6.21 mm/sec, A-7.04 mm/sec Motor drive bearing H-4.22 mm/sec, V-8.22 mm/sec, A-8.64 mm/sec This motor is connected with high pressure pump. I have decoupled & checked the motor in solo run test. but no improvement same vibration is persisting in solo run test. Spectrum appears like 1X,2X,3X,4X..... multiple harmonic...
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Axial End play limits for motor provided with ball bearings

vikramdeeps ·
Hi Guys, Can you help me with Axial End play limits for motors provided with ball bearings.Any standard which says the limits for end play for motors?
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AC motors

dos80 ·
Can anyone recommended where I can find case studies and pictures on AC motors that had issues with them and where found through IR.  I usually take vibration readings on motors and that's how I find my issues but a new customer wants all AC motors scanned.  I am a Cert Level 1 thermographer and have scanned plenty of electrical panels just not sure what to look for scanning  motors.  Thanks in advance for your help.
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BALL BEARING FAILURE ON 1,3 MW / 6KV SCHORCH MOTOR IN REFINERY

George NV ·
Preventive - predictive maintenance team has called for withdraw and repair large electric motor , vertical , 1,3 MW , 6 KV , 745 rpm driving large multistage pump . Finding was DE bearing wear  ( inner ring ) . That was confirmed upon disassembly and inspection .  Strange finding is the wear pattern found on the outer race of the angular contact ball bearing , 7330 B , mounted inboard on top side . This bearing only for axial loading . Next to it , outboard is a 6330 C3 brg . This...
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Can Vertical Motor be Run in horizontal position ?

jakka ·
Can Vertical Mounting Motor be Run in horizontal position for testing purpose? we are having a vertical mount motor which is having temperature issue on DE side can be run the motor in horizontal position, will it have any effect if we change the mounting(both sides ball bearing)  
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Cement MIll Fan high vibration.

rajathopuri ·
Dear All, I am facing problem in cement mill fan over the months, vibration readings are high at Motor DE , Motor NDE and Fan DE side horizontal vibrations are. since horizontal vibrations are high, and generating frequency 1Xrpm, i have decided to balance the coupling, i tried for balancing i was successes to reduce the some vibration, however still vibrations are high on motor side, please refer below table and kindly advise, what should i do further to reduce vibration. all FFT spectrum...
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Cooling Tower Fan High Motor Vibration

Andy$ ·
Dears, We have a CT made by 22 cells, separated in 2 Blocks. Last week one of them tripped because of HH vibration on the Motor side (the limit is set to 9mm/s). I checked the spectrum and I found a “strange” frequency that I have never seen on these fans (around 88Hz). The behavior was confirmed by the SKF portable instrument. The speed of the motor is 1485 rpm and fan speed is 106 rpm (6blades). I suspected some looseness so I suggested to make an inspection, looking for some loose bolts...
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Cross Phase analysis issue

Hossam 2 ·
Problem is in motor if atox mill (insaldo) The free end has a 4xts dominent vibration we have balanced it to reduce one x from 3 to 0.3 mm/s vut still over all value is 5.5mms wiz 4xts sharp  The phase relationship is weired as 180 phase difference between the drive end and non drive end in the vertical direction ..i suspect misalignment problem and the other issue is that no sensors give exact reading across the coupling specially in the gearbox side always give real value in the motor...
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Crusher vibration problem

Velmurugan ·
Sir, we were facing high vibration problem in our crusher only at motor bearings exactly at running speed motor(Motor rpm 1500) & crusher vibration was very normal.I recommended for motor pulley unbalance(Because in all H,V,A direction vibration persisted in motor) Our maintenace people inspected the shayaji crusher rotor (hammer type rotor) & some of the hammers found with wear. They replaced all the hammers recently based on ou client advice.Luckily the motor vibration came...
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DC Motor, speed wandering

Xracer ·
Have a 250 hp DC motor, shunt wound and when capturing motor speed with a strobe light, I'm unable to completely stop the shaft. My target will keep moving around. I would say that this wandering is +- 5-10 rpm. This is both loaded and unloaded. One should be able to stop the shaft with a stobe light regardless if its connected to a VFD or not? Right? X
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Electric Motor Bearing Grease - quantity and frequency

TroyS ·
I've calculated a whole bunch of grease quantities and ideal intervals for our electric motors in a plant environment.  To manage the work load we've fixed our routes to 60 days.  This is where my question comes in -  I'm not concerned about adjusting the grease quantity down when the calculation tells me to less often.  Example  - calculation tells me to add 100 grams of grease every 120 days and set our program at 50 grams every 60 days.  Where I get concerned...
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Electric Motor Defect Frequency

Alvaro Loayza ·
I want to share this case that we had 2 weeks ago in our plant. Equipment: 500 hp 1780 RPM Toshiba motor With 6322 Inboard Bearing Fault: BPFI with sidebands at turning speed. Peakvue Amplitud 0.75 G's rms. Report: Scheduled replacement for 30 days. Trend supported recomendation. Results: Maintenance lubricated bearing and amplitud dropped to 0.2 G's RMS. BPFI with sidebands was still present. They replaced motor bearing 45 days later after first report. Visual inspection didn't show any...
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high vibration in motor side

vishal sharma ·
sir we are facing  high vibration  at motor side .its a 113 kw motor.sir give ur suggestions  on urgent  basis
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High Vibration in Roller Press Motor

vidya Sagar ·
Hi Friends,                  In our plant we use roller press for cement grinding and in one of the roller press we observed very high vibration in motor of both rollers i.e., fixed and movable.So we...
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High vibration on 356 HP Motor- 742 RPM Vertical Pump- Sea Water Duty

vipul@cmc ·
Hi , We are facing High Vibration on 356 HP Motor- 742 RPM Vertical Pump- Sea Water Duty Kindly find the attached sheet with all details - Kindly give what could be the possible reasons for high Vibrations. Regards,
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Good motor application guide by GE

Dan Timberlake ·
https://www.orbit-magazine.com/wp-content/uploads/2016/03/GEA32339-Elec-Motor-Cond-Monit-App-Guide_R3.pdf
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High axial vibration at 18x in a flowserve pump electric motor.

Alvaro Loayza ·
Hello, I have 10 identical flowserve water pumps. They are driven by a 1620 HP ABB electric motor. In 9 of these pumps I have very low amplitudes of vibration in every direction at electric motor. (0.3 -- 0.5 mm/s) I supposed this is because of system stifness But in one of them, specifically in axial direction I have very high levels of vibration (7.1 mm/s at exactly 18x) This shafts turns at 1180 RPM. So frequency is aproximately 21200 CPM. This vibration is higher (7.1 mm/s) as close to...
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How to set Magnetic Center of the motor

Engr Jamil ·
We are having one motor for maintenance 3600HP, 6.6KV, 3582RPM. In Solo testing it shows the axial movement of the rotor shaft around 1.3mm back and forth which must be stable in the magnetic center line. We are facing axial vibration 5.5mm/sec and radial around 3mm/sec. The vibration is fluctuating form 1.7 to 3 radial and 2.7 to 5.5 axial. How can we adjust the magnetic center to keep the rotor stable. Also what is the acceptable unbalance for power source because we are having almost 10%...
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How to use MCEmax to check air gap condition of DC motor?

Lampard Nguyen ·
How to use MCEmax to check air gap condition of DC motor?
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ISO 10816

MarkSl ·
Hi,   Does anyone know if ISO 10816 can be used for exception testing of a vertical motor   Thanks Mark
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Loose stator winding

Lampard Nguyen ·
Dear Experts,   There is wound rotor motor, 6 poles, 50Hz, 992rpm operating, 800KW, 6.6KV, coal milling motor. It was the first times I performed Vibartion analysis to that motor. In FFT velocity spectrum, It indicates some peaks of 2*FL and...
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Limit of Temperature in Motor Bearing and Motor Body

Jay Paul ·
Limit of Temperature in Motor Bearing and Motor Body   Thanks in Advande
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Motors Hunting Mag Center

Mile High_PumpFE ·
Have a pipeline customer that has three 3000 HP motors driving main line pipeline pumps that are hunting mag center. These are Mitsubishi AC induction motors, 4160V, 60 HZ, 360 FLA, rated for 3570 rpms..... these motors are set up so that any given motor/pump combination can be run through the one VFD on site, and the other pump/motor combo can be run across the line at full speed (always running two units at these stations..... one in VFD to throttle flow, one across the line at full...
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Motor natural frequencies

Dave Reynolds ·
Wanting to clear the air.....   I recently posted a response, shown below:   Electric motors typically do not have natural frequencies/vibration below or at running speed, check this off the list. The motor mounts to the gearbox via a cface...
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Motor running in offset from magnetic center

Abhi03 ·
Dear All, We have facing a issue with one HT motor with axial fan load. When we start the motor (consider the motor has stopped in offset from magnetic center) it continues to run in offset up to rated speed (996 RPM) condition without trying to attend magnetic center. However when we reduce the speed bellow 500 RPM it comes to magnetic center and continues to run at magnetic center. The motor is designed with floating bearing and load DE side bearing is axial guide bearing. The motor rotor...
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Motor shaft axial movement solo run

vikramdeeps ·
Hi Guys , Usually I have seen axial movement in motor shaft during solo runs but I am curious to know that How much axial movement is allowed in solo run in motors with sleeve bearings and anti friction bearings?   Guys Usually I have seen...
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Motor Status Model 301

montaser ·
Dears, We have the subjected instrument in our section but unfortunately we didn't use it any time before, can you help to explain how to use to do motor current analysis, and attache any manual if found. Best Regards
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Orbit analysis for electric motor

Alvaro Loayza ·
Hello to everybody, We're proposing to implement orbit analysis in our 3500 HP sleeve bearing electric motor. We collect data only with accelerometer and make standard FFT and waveform analysis. Do you have an aproximate cost or proposal for proximity probes to install and recommended software you could share with me? Greetings.
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Reg:High vibrations at H.T Motor in Horizontals...

abhiramkompella ·
Dear experts We have Primary air fan of 1675Kw & 1485Rpm ...Motor is of BHEL make and the vibrations of motor are going high i.e., 6.2mm/s at Nde, 5.4mm/s De horizontals at motor...In the spectrum we have 1X running rpm of motor ...The 'g' value of motor bearings are 0.106g no abnormal sound from bearings...We have inspected on "impeller,coupling,looseness,soft foot,alignment and further went for motor solo trial" In the solo trial of motor...
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Test Bed Motor and Blower

Avinash Thawani ·
I have motor and blower currently the noise is 100 db.I want to reduce the noise, can you please advise how to remove the noise. Please find picture attached.
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Test stand vibration

tcvib ·
We have a motor test stand that I have a question about. We have had a motor that is failing our vibration acceptance tests here. Our spec for overall in .06 in/sec. The motor in question has been sent to the shop and measured good. The issue is that we run this motor at 480V instead of 2300V nameplate voltage. We normally run these motors at low voltage with no issue. The test bed is "isolated", but we have vibration to the floor up to .08 in/sec. We have .03 in/sec Vert and Axial and .12...
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Vertical Motor 1x peak w/sidebands

rgf12 ·
I have a cooling tower pump/motor (Flowserve pump/GE 5KV8660 motor) operating at 500 RPM where I'm seeing sidebands around the 1x peak. These peaks have reappeared and where seen prior to the last rebuild in 2013. My question is what could be driving these sidebands? They don't correspond to any bearing fault frequency and the signature is very clean with a large 1x and little else. As far as I can remember I've never seen sidebands like this  before and I'm sure it is not a good sign.
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Vertical Motor Vibration On Air Cooled Condenser

Doc7 ·
Hello,   Are standard vibration severity charts applicable to motors vertically mounted on a gearbox over an ACC axial flow fan?   I have several dozen 1800 RPM motors mounted on  single-reduction gearboxes to fans with nominal speed...
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VFD Motor solo run

vikramdeeps ·
Hi guys,I need some suggestions regarding VFD motor solo runs trials: During solo run vibrations check ,At what speed( max speed or operating speed?) we need to take the vibrations?
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Vibration at 3.1x order in Motor

SHANS ·
Hi We are currently facing a high vibration issue in one of our Oil water transfer pump motor (Horizontal pump) in our midstream facility. Its a 45 KW (Make:Loher) motor running at 1475 RPM. Both DE&NDE bearings are 6316 C3. Motor NDE : H- 1.0 mm/s, V-4.5 mm/s, A-3.7 mm/s Motor DE : H- 1.2 mm/s, V-2.7 mm/s, A-3.9 mm/s Motor is showing very clear distinct non-synchronous peak at 4560 cpm (3.1x) and minor peak at 9120 cpm. (Checked with high resolution spectrum also)...
Reply

Re: Crusher vibration problem

Edwin de B ·
Hi, The change in motor vibration doesn't seem to be directly related to the crushers hammers. But there may have happened something to the motor during this maintenance. The first spectra show not only a high 1X but also some higher harmonics of it. Those are also gone after the maintenance actions. Therefore I think is was caused by some looseness or clearance at the motor which is not there now. Was the motor loosened to remove belts during the maintenance? I think the mounting of the...
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Re: Crusher vibration problem

Velmurugan ·
Hi, Thanks for the reply.Spectrum before hammer replacement shown the dominated/greater vibration only at 1X rpm of motor in both NDE & DE bearing of motor and 2X,3X amplitude were about lesser 2mm/sec.There was no looseness at all in motor base & bearing and belt was not removed so far.This is crusher A.Let us keep away this discussion for some time. Let me share you another interesting thing about crusher B(Stand by of Crusher A).Compare both crusher behaviour and suggest your...
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Re: Crusher vibration problem

Velmurugan ·
In both crushers high vibration falls only at 1X rpm of motor ie 1500 rpm. I already attached spectrum of Crusher A motor and here i am attaching crusher B motor spectrum.
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Re: Crusher vibration problem

Edwin de B ·
I assumed the crusher was at lower rpm than the motor. But they have same rpm you say. You should take a measurement and zoom in on 1X rpm. There will be a small difference in motor and crusher rpm, due to a few % slip on the belt. That way you can determine if the big 1X is from motor or from crusher. You should know that a high vibration on the motor could still come from a source in the crusher. The crushers mounting will be a lot stiffer than the motor mounting. I also have some...
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Re: Crusher vibration problem

Velmurugan ·
Motor-1500 rpm Crusher-675 to 750 rpm Belt driven High vibration persisting only in motor at 1500 rpm(1x of motor) Crusher vibration is very normal.
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Re: Crusher vibration problem

Edwin de B ·
Are you 100% sure the high component is 1X motor and not 2X from the crusher?
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Re: Crusher vibration problem

Velmurugan ·
My suspection is that they have replaced hammers in Crusher A.there may be a chance of rotor weight increase than the older weight.I don't know what is the each weight of new hammer they replaced.could this be reason for reduction of high vibration in motor. Let us imagine that motor pulley got unbalance and we get high vibration in motor.If i increase the weight of crusher rotor mass by using higher weight hammers.will my motor unbalanced vibration reduce. If yes means is it happening in my...
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Re: Crusher vibration problem

Velmurugan ·
Sure it is 1x of motor
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Re: Crusher vibration problem

Velmurugan ·
Your suggestion may help me.I never had this type of problem before. I am still doubt about motor pulley unbalance.That unbalance got compensated somehow after replacing crusher hammers.Am I correct?
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Re: Crusher vibration problem

Edwin de B ·
The force initiated by unbalance only depends on rpm and the unbalance itself. But the actual deflection of the structure can vary because the stiffness of the construction varies with different load. Espesially belt driven. Whatever happens in the crusher can not influence the unbalance of the pulley. What can happen is that your pulley is worn eliptical. under different loads the belt can be in a different position where this is more ore less present. Also over time (after running one...
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Re: Crusher vibration problem

Velmurugan ·
That is V belt.
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Re: Crusher vibration problem

Velmurugan ·
Tell me one think When motor & crusher(Under coupled by V belt) condition- High vibration in Motor NDE & DE bearing in Horizontal direction comes 30 mm/sec. When i decouple the crusher from motor(By removing V belt)- High vibration in Motor NDE & DE bearing in same Horizontal increased to 55 mm/sec. Why under motor solo run it is high & why it has halfy reduces under coupled.
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