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OLi

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Reply with quote  #16 
One bonus out of my Father, Gösta's book part 10, cases from reality and as a teaser these parts are included in the complete book: antifriction bearings, papermachines, fans, rolling mills, noise, blade resonances, crushers, grinders etc., pumps and hydro, various, electrical motors, steamturbines, gbx's, all fully illustrated part from this example:

Elevator. A govnmnt elevator in a house got vibrations in the basket and drive. On motor elevator 1 it was 30 mm/s free end vert and 10 mm/s horiz. Balancing was performed. 30 g reduced levels to 8-10 mm/s any further trim deduced severe instability and high sensitivity possibly triggered by a close proximity resonance. Knock test revealed a motor critical speed at 1385 RPM vert and 1320 RPM horiz. Set speed was 1398 RPM so high unbalance sensitivity was no surprise reduction of speed to 1250 RPM gave vibrations at less than 3.5 mm/s and no noticeable basket vibrations. Elevator 2 had a resonance at 1450 RPM and motor vibration 4 mm/s the difference was that no 2 had a shorter support beam and by that it was stiffer and that give a little bit higher critical speed and was accepted.

They are a bit old, CSI 2100 is used as a general analyzer and it was published 1997 but machinery problems are the same and timeless I think.

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OLi

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Reply with quote  #17 

So i am now at the next part of the major opus of the 38 MW VFD motors.... only 2 left then but they will be in the book.....

CBB Boss called again, a long time after Milan midsummer episode... "Can you go to the NIJ plant in Hiroshima?"  Why? "You will be promoted as CBB Supervisor, need to do nothing but Supervise the unbalance test according to ISO/API etc. besides Samurai wants you and he is pointing finger like Uncle Sam... Joint chief messed up disaster board also want's you there to fix any quirks in your normal diplomatic fashion if required." Ok, I go but you pay me for the promotion, Supervisor is extra cost. " Ok, but this time you keep lo profile, when we sent you to Milan we wanted to find out the reason for trouble so we let you loose as we normally do so you could bulldozer out the Gremlins in the diplomatic way you normally kick all stupids asses and you did so it went according to plan. In Hiroshima on Japanese turf you keep lo profile, let them do whatever as long as final full load test is good and everybody happy, put your technical fancy pansy ideas about correct measurement and that useless rocket science aside and act as Supervisor put on your pointy hair boss disguise and go chop chop." Yes Boss, sure Boss. "By the way NIJ say that you need not to bring no measurement devices as they are modern and will provide all you need." Yeah right Boss, I will do what I need at my own discretion as promoted and all.

So when you are promoted to a Supervisor hired gun for a 3-letter corp on requirement from customer 3-letter corp Samurai that is your friend it means one thing, CBB don't want to sacrifice their own staff as they are obliged by the union to mop up the residual parts after the event if it comes down to the long night of knives so they hire a dispensable hired gun. By the way, Swiss Finn w/o knife was no where to be seen. I was the solo and only CBB mimicking pointy hair boss on site, I never been good at that, my Ranger Sergeant training peeps thru...  I was however confident that if push come to show the Viking Sword would bite the Samurai Sword any day of the week after our intro opening discussions and backed by the hidden Thor's Hammer that all true Vikings have as a last resource the outcome was never in doubt in my mind. Not that it came to that. I was lucky, machinery behaved reasonably  and got away with "lo profile" but you never know, better prepaired than run over and stabbed in the back as a Supervisor.... Like the CBB super girl matador of the VFD party tent content that refused categorically to return to South Korea after first stint on huge VFD commissioning since Koreans only screamed on the project meetings and had no constructive input, their loss, bad luck for them it may well increased project time 50%.
So I was gathering strength, brazed myself for some more diplomatic interaction with my friend the Samurai, now at his own turf during flying and Shinkanzen bullet train. .So I donned with my faithful ME52 vibration analyzer, balancer that I have developed my self top down and know inside out since I made it, developed it, software, hardware the complete shebang and sold in 350 pcs world wide.... also in a boiler suit pocket friendly size and left my 2120 back home.
By the way I was on ancestry track my Father Gösta ventured the same way in the 50's to Japan also ending up a hero a more time consuming endeavor at that time but that is another story I will tell later.
So a nice morning I ventured in the site/factory and there before me on a 13 m hi pagoda of wood beams and rubber elements stood the complete device, motor, gbx, compressor. i was so shocked I almost turned at the gate but I brazed myself, went in to the 7-11 that they had inside the gate to get a coffee to recover from the shock-----
So they mimicked the paper figures I discussed with my other friend the rotating engineer from end customer Scale petro corp that I prepped on foundations and the requirement of stiffness for such a huge piece of machinery...  Bedrock was my suggestion that would be quite possible in Norway I thought. I was truly disappointed and is surely was not conforming to CBB foundation design rules. So I thought the Japanese had free styled some to over some compressor problem but no it was a true copy of the not yet built mounting in Norway I would later find out.

So the setup was as  NIJ is a huge 3 letter corp with there own power plant they had to pull a substantial extension cord from the power plant and run it specific for the 38 MW motor testing but that is a minor inconvenience for a corp like that.
Next was that test would be with inert gas that exactly mimic natural gas properties. I didn't know that was possible but it is an you always learn. So yard was full with storage tanks and stuff and pipes and if you compress the h out of gas it get hot as h and need cooling so it was a impressive mess to do that.
Party tent was by the way a wood hut in Hiroshima with the VFD and everybody played Baseball all lunch breaks all around everywhere around machinery and I bought a "keps" a baseball hat that promoted a baseball team out of Knoxville TN, that I never knew existed, you always learn. Every shift change the local crew gathered around the local Samurai and got the corp gospel and did sing the mandatory corp hymn for the well being of the corp an dit's Samurai's I guess, also at 2 in the morning.... Impressive.

So this was like FAT of the complete pack. On a side note to make the mess complete, testing was slightly delayed as Scale possibly the rotating engineer had demanded a abnormal tight bearing setting during FAT in gbx factory in Texas in contradiction to the advice of the OEM gbx manufacturer where the gbx as a well trained Texan immediately wiped all bearings due to tight clearance. He was not always lucky my friend the rotating engineer.... and Murphy also have presence in Texas good to know. I also have a ME instrument at the uni of Texas, Houston....
So we started to run and first run would include a overspeed and it did and all was fine.
Despite the Bently data was even more crap than usually as I previously said as signals btw. proxys and rack was pulled several 10ths of meters in same cable run as the VFD drive cables carrying 38 MW power at times..... Rack was wrapped in thin foil with only cosmetic result, I asked if I could get some foil to make a tin foil hat and the Japanese stared at me.
Japanese had their own system with every sensor you can think of that worked perfectly that was "secret" and not for Gai Jin's to look at but I sneak peaked..
In short, every run included overspeed and my strict orders was that I would supervise that and I did. I ratted on the Samurai way of running the motor and CBB made the whip fall heavy thru Tokyo superior pointy hair mole whacking and the Samurai in one instance, one only waived his self appointed right to shorten motor rotor life length and at that time he slightly nodded once in my direction and I waved back with a thumb up. I kept reporting warranty violations at no result. Resistance is futile, you will be assimilated. I asked if I could traverse the abyss and take some manual readings during a test run and answer was "with what?" With my vibration analyzer naturally dumb ass I am a vibration consultant I do not travel undressed. "with respect to your own health, no we don't think so Tim". I am not that diplomatic and if would be a show down at Hiroshima corral btw Samurai and Viking sword I for sure would not be w/o data... Yes it was vibrating a bit, nearly like a Las Vegas working girl as previously mentioned but only absolute bearing vibe due to the foundation design, eddy probes where within spec and who cares abt. unreliable absolute bearing vibration data.  
Finally we made the unbalance test and the FAT with customer Scale presence.
Unbalance test data  was totally useless due to the VFD interference and was never used so it was fully according to plan and it was anyway written in the contract that the test data would only be information and not used to interfere with important things like acceptance and commissioning well played CBB.
Noise measurement Norwegian came down the ladder on shaky legs and said it was vibrating slightly there and I said yes sure on that pagoda foundation it will be better back home on bedrock and I honestly believed that at that time luckily. It was not the case IRL I am afraid...
So FAT was declared a huge susses but only another quirk solved by yours truly's diplomatic skills...

Dutch Scale guy responsible for a go or no go on site evaluation of FAT first was stunned by the lo quality of the data as he arrived and I told him it always look like that but sometimes marginally better and he got dark eyes slightly flashing and I made a new friend that was only fixed a couple of days later. This guy was a former Bently employee since 20+ years involved in the development of the finest sytem on earth only skipping ship to Scale as GE invaded his homeland... That's for my lo profile capabilities.. So he needed a peep on the data. Could he initiate miracle software on his own PC? No surpeise he had only web surf rights and maybe likely to look at Las Vegas vibrations.. Could he borrow a box from NIJ, no safety prohibit that. Could you rent one down town? Sure in Japanese Windows, Yikes.

I happened to know that the CBB VFD matadors were trusted to have full control of their PC's as they were trusted with multi million USD machinery and sometimes required some force and slack to tame the beasts. 
So I introduced the Scale Dutch to the Swiss super girl VFD matador with control over her PC so they had a Sunday hackaton and vibration introduction training Bently style and that guy is the only one that ever said that the data was good and all good to go and at that time NIJ was already 50% on the tear down to keep schedule for next test waiting for nobody and nothing since they had perfectly good shadow data and waiting for no stupid Gai Jin input.
So what ends good is good and a site you walk away from alive is a good site, in this case the destiny was whipping up things for me and the motor.
For motor it was dropped keyside when loading to leave for Europe diplacing brg assy and mount like 42 mm vertically and a bit horiz so back to Aros for factory repair. For me we flew home by Turkish airways first class and some trouble
awaited me but I place that as a cliff hanger in to the book. CBB payed the somewhat stiffer invoice maybe with a grin this time.... It is now IRL a 3 year pause as the Norwegian site was not prepared despite all delay and talk of Antonov air transport etc. Machinery after completed testing sit by the dock of the bay overlooking the North Sea and Atlantic and with a mere cover of a Tarp, no conservation and only CBB strict requirement on space heater but at least 1 gbx suffers from this in the future IMHO, suckers, wasters of machinery..... 
during this the lazies make a static sync freq grid compensator from ABB to scratch together some electrons for "my" motors as the cable along the Hardanger vidda is a bit narrow for the site. It is basically another huge DC/DC converter as phase comp device. It eventually works perfectly! Also a 1000 welders pull together the pipes and it is for awhile Norway's biggest expansion project... Then they finally build the house for my friends, the gentle giants.... and they move in. During this the site is kept in full operation steady delivering 20% of UK natural gas consumption.... Impressive I must say.
In next part a rotating engineer utters the ... words "that is in my view unorthodox" and the consultant answers with " I find that stupid but in other words" and we part agreeing on disagreeing that is a safe retreat among Vikings not risking any backstabbing more than the normal quota (we don't want any war hammer fights on site) and epic 23 day 3 run balancing session that nobody want to pay for....but do solve all OEM and rotating engineer troubles in one strike and for the full future by just pure luck and that is something a good consultant really need to be able to call upon when in dire straights and me and my sons do are blessed by that for some unknown reason.  Not the least the Swiss Finn w/o a knife that camp out in the Alps shutting his Swiss bank account like a greedy Berg Troll just because the Japanese stopped paying him, what reason would that be among friends....


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Good Vibrations since early 1950's, first patented vibrometer 1956 in the US.
http://www.vtab.se
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