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Good morning to everyone, some strange spectra today during analisys. DIESEL TCG 2020 V16 (caterpillar) connected directly on MARELLI generator Speed: 1500 RPM I found about 87Hz as exactly 7 times firing frequency (1/2 RPM) till 10 mm/s as below Lot of time i found some problem with...

Hello to everyone, i have really strange case about cardan shaft problems. I attachment you find some photos about one of the cardan shaft failured. This is paper mill company and have big trouble during last year. All motors are DC motors with one AC/DC drive per unit motor. Some indications...

I'm creating a new company branch as predicitve maintenance for customers so i need to buy some instrumentation. I've already bought a vibration portable instrument but because i want to provide more services i'm looking for the rest of instrumentation. Often the best opporunity is in exibitions...

Hello Guys, in attachments you found some photo about strange gearbox tooth pattern found. Before the inspection i made some vibration measurement on it discovered this:4 -1XM in axial 13,5 mm/s -2XM in radial 16 mm/s -1XGMF 2mm/s THis machine is forming roll in a papaer machine...

Hello Guys, in attachments you found some photo about strange gearbox tooth pattern found. Before the inspection i made some vibration measurement on it discovered this:4 -1XM in axial 13,5 mm/s -2XM in radial 16 mm/s -1XGMF 2mm/s THis machine is forming roll in a papaer machine...

Hello Guys, i have 2 data acquisition with 2 waveform one with impulse and one without. I made some calculation with my instruments and it is very easy to evaluate impulsiveness of the waveform. Why, instead, Kurtosis seems have missed this impulsiveness of the waveform? Let me know about your...

Just today I learned about the existence of synchronous magnetic reluctance motors. I'm trying to learn about the theory behind focusing on vibration measurements. I think that is as normal motor with some efficiency improvement but i think that in general some different vibrations could came...

Good morning everyone, i know during braker closing on 132KV system, transformer have a particular behavior. Firstly high current absortion called magentizing inrush current, this current have 10 times steady state current, have distortion because of core saturation. There are considerations...

Hello, i heard about possibility to make some measurements with gaussmeter (or similar) to check about winding condition of the motor, anyone have experiences about it? Could be usefull more than vibration analysis for electrical poiint of view? Could you suggest some device to try? Regards

Hello to everyone, this post came from another post but i want to threat in different because different object. The question is EASY[lol] I have VOLTAGE, CURRENT and V/I ANGLE I want to calculate the real energy consumption in a year. What formula i need? please give me a description of...

Hello guys, i have a very strange fact. i have 7 fan vertical motor-pulley-fan in a steam condensation field and for every motor i collected phase-phase voltage, phase-neutral voltage, and phase current. All the motor are mechanically and electrically equal and have 380V, 88A, cosfi=0,82 data...

Hy guys, i have a boiler food pump 278Kw 6000Vac 3000RPM have a recursive bearing failure. There are # 2 NU317 and #1 6317C3 on DE. The failure occur at 6317 bearing and it is a classic fatigue damage as described in bearing detection failure manual (SKF or FAG). This bearing life is aprox 6...

This is strange request, What do you will use to acquire 2-3 Hz? Other than specific sensors(seismic) there are particular techniques using normal 100 or 500 mv/g or normal velocity sensors?

Hi guys, my customer have a Turbo Blower with 2 fans coaxial on the motor shaft but customer told me the motor speed is 9600 RPM at 50 Hz. Could be possible? Anyone have any idea? Regards

Hi guys, we had a 3 phase current unbalace problem due to a ph to ph short (high negative sequence). In this situation 2 phase increased and one goes near to 0. This problem could be induce on a thyristor dc bridge some type of malfunction? This could be cause a broken on thyristor or motor...

Hello guys, what do you think about ceramic Bearings frequencies? The fault frequencies are the same as normal bearing? What frequencies are for HBC 7019 Thank you

Could you share your practical monthly (or more) check list about maintenance of your cabinet? Regards

Hello to everyone, i have a transformer ABB ADDA, 35MVA, ONAN TYPE, pri:138KV sec:11KV with only primary and secondary winding oil radiant cooling system. 132KV line is a star connection and secondary is delta connection. The connection is 132KV line >> trafo >> generator 11KV Consider generator...

Hy guys, i'0m talking about 45 MW turbomachinery and i'm tring to decide the best installation for vibration sensors on all components. Because i found lot of discussion about, i'd like to know your opinion about this question: pickup shaft movements with proximitor (#2@45° on vertical line or...

Hy Guys, this is very simple post but it is not so clear with my knowledge. When i want to change reactive power in a Generator i have to control the excitation current and this is a fact... Looking at formulas and power triangle i can assume the S=V*I, P=S*cosfi, Q=S*senfi What exactly...