High Vibration in Compressor Motor

"Your customer"?

What is your relationship? Are you the motor supplier?

Maintenance contractor?

Has your customer had a competent service tech check the fan and NDE bearings?

Have you, or your customer contacted the motor manufacturer?

What have you done so far? Anything?????

Dear Lyn,

We are a maintenance contractor and machine was supplied by Teco Westinghouse which was commissioned by us in 2010.

Regards

You're the maintenance cotractor and you're asking strangers for consulting help?

Seems a bit odd.

Hire a motor service tech to come check out the motor and compressed.

Free advice is worth what you pay for it.

Check the fan and NDE bearings.

HIRE SOMEONE WHO CAN SEE THE MOTOR AND REPAIR IT.

EARN YOUR PAY!

Dear Lyn,

First of all we are here for discussion and thankful for your Nice comment..

Regards

Ego?

Truth!

You are being paid as a maintenance contractor.

Do your job.

Have you checked the bearings? Fan? What have you done?

That is not a difficult question to answer, assuming you have done anything.

What have you done? Anything?

If you want free advice, at least tell us if you have done anything.

Dear Lyn,

I have checked this machine and communicate some activity as:

A: Change the lube oil to entire unit as it seems to make oil whirls in Motor bearings sumps.

B: Check all the Vibration probes and transmitter.

C: Cleans the entire cooling tubes to ensure that it might be have air turbulence in cooling circuit.

D: Check the healthiness of bearings.

E: Check the alignment of Motor & Compressor.

F: Tightness of motor foot bolts to ensure if any soft footing problem in motor base.

G: Check any Voltage or Frequency variation in power line.

H: SITU balancing if any imbalance mass created in Rotor.

The machine was tripped due to high vibration so the above side activity started and finish as communicate:

1: Change the lube oil.

2: Check all the probes and Transmitter.

3: Cleans entire cooling tubes with compressed air.

4: Check the bearings and found in good condition. No any marks or abnormalities in bearings so cleans and fitted back the same.

5: Alignment found disturb as .6 in redial & .4 in axial so realignment the machine and alignment in .03 in both sites.

6: Voltage & Frequency is stable and no any variation at all.

7: Set DE side vibration probe with 7.26mv and NDE with 6.7mv. Check imbalance mass with single plan SITU balancer and found only 6gm unbalance on rotor so no need to balance the rotor.

The no load vibration was 10 - 11 micron for DE side and 15-16 for NDE side. Coupled the machine with compressor on load and found everything fine and no any abnormal behavior, hotspot or any kind of temperature in machine. The machine runs approx 10 days without any trouble.

Now the vibration accelerate and reach at 42 micron even we set 50.8 micron for tripping. Now we want to know why vibration increase in only Motor NDE side.

Regards

Quite a big and high speed motor that is, I have no inputs other than you should contact aftersales of Teco or Atlas copco about this. They know better than you do or anyone else in this forum. Its a tremendous liabillity you got there.

You measured the amplitude of the vibration, did you reccord its frequency ? This could bring you to an explanation of what you noticed.

your story goes south right after, "cleaning the cooling fan with rags", is this the manufacturers recommendation?

OP is the, "maintenance contractor and machine was supplied by Teco Westinghouse which was commissioned by us in 2010".

I'd think he'd know. He commissioned it.

Am I being too harsh?

1. Vibration is typically measured in units such as 0-x "g", or 0-x mm/s. Not in microns.

2. Fredski is spot on with his advice: "If it worked properly yesterday, and fails today: WHAT changed?"

3. Since the cooling fan which was "firmly cleans the Motor cooling fan with rags", is on the NDE side; it is possible that is where the vibration is originating.

A motor that large will have a cooling fan large enough to need balancing.

May be microns he meant was clearance to something

Dear All,

Thanks for your valuable input on high vibrations.

As the machine run very smooth and no any unwanted sound or temperature even vibration also run in limit as 20 to 24 microns but it make spike some time and goes beyond limit which we set for tripping.

cc Kilowatto: This is 3 stage Booster Air Compressor and equipped with Bently Navada 31000 Proximity probes and 990 Transmitter. The measuring unit of vibration is in micron.

µ = mm/0.0010000.

Regards

I'm with RAMconsultant on this one. It's highly likely that in the cleaning process, someone said "Hey look, there's a thing-a-ma-jig stuck on the fan blade!" and moved or removed it, or if they discretely put it back on once they figured out their mistake, it's not in the right location. That was likely a balancing weight. You may need to have the fan re-balanced now. I have seen that happen in more than one circumstance, and on one of them, it resulted in the destruction of the fan.

And it is plausible that the fan being out of balance may create a vibration at one end of the motor and not the other, it would have to do with the axial and radial deflections it causes.

I've suggested checking the fan twice, Ram, Fredski and you (and maybe more) have suggested the fan may be the problem.

I keep going back to the fact that OP is being paid to perform maintenance on this equipment and doesn't know how.

He wants free advice from unknown strangers who have never seen this equipment and have been given no meaningful information.

Once again I'm suggesting that he pay someone to evaluate and repair the equipment.

In your comment:

IN November beginning the customer had routine maintenance and firmly cleans the Motor cooling fan with rags. After testing of Compressor they started but motor tripped on high vibration. Checked all the connection and Vibration probes and found everything was normal.

It seems very evident that your FIRM CLEANING may have damaged the fan or its balancing weights. Have the fan re-balanced or replaced then continue your training of the maintenance personnel in proper handling of precision balanced equipment. I have a feeling your technician was too FIRM in their cleaning.

I would be holding the "Maintenance" company responsible for the repair and the cost of the repair. I suggest the company that owns the compressor hire a different company to fix the vibration issue and deduct that amount from the "Maintenance" invoice!

Great Input..

LYN: ""I've suggested checking the fan twice, Ram, Fredski and you (and maybe more) have suggested the fan may be the problem.

I keep going back to the fact that OP is being paid to perform maintenance on this equipment and doesn't know how.

He wants free advice from unknown strangers who have never seen this equipment and have been given no meaningful information. Once again I'm suggesting that he pay someone to evaluate and repair the equipment.""

Orignal Macgyver: ""I would be holding the "Maintenance" company responsible for the repair and the cost of the repair. I suggest the company that owns the compressor hire a different company to fix the vibration issue and deduct that amount from the "Maintenance" invoice! ""

I am bit confused that what word have to use here.. By the way the problem is solved now.. I will be remind to make a thread here in future..

Thanks & Regard

Robbin