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  1. LaffeyDD724

    Maintenance techniques on medium voltage contactors.

    You are going to have a big surprise with those starters someday and it's going to be a burn out or a blow out which can be quite nasty and then it will cost an arm and a leg to get those motors operating again. If it were to be taken care of sooner rather than later it would be pocket change...
  2. LaffeyDD724

    Maintenance techniques on medium voltage contactors.

    It sounds like to me from what you are describing that the receiver contacts for the stabs do not have enough tension on them to maintain adequate contact pressure on the stabs and this has caused hot spots to develop at times and has eroded away some of the stab contact surface by pitting the...
  3. LaffeyDD724

    Maintenance techniques on medium voltage contactors.

    Is your cement plant close to any other industry? Do you think the atmosphere in the cement plant is the culprit? If so what do you think is present in the plant that would attack the silver coatings. Do you have the same problem with the copper items also? Do you have cement dust in the MCC...
  4. LaffeyDD724

    Maintenance techniques on medium voltage contactors.

    You did not state what type of industrial plant you are maintaining. I will just make this statement. In the pulp and paper mills where I worked, believe it or not, the hydrogen sulphide gas generated in the pulp mill section was all over the mill area and the hydrogen sulphide gas will cause...
  5. LaffeyDD724

    300 HP GE motor

    I did some research and found that a tapered roller bearing, that is typically used for belted loads would not be suitable for a coupling application. The reason given is that the tapered roler bearing requires side loading to keep it healthy. If that type of bearing were to be installed on a...
  6. LaffeyDD724

    300 HP GE motor

    Keith, It has been a while since I ran into that problem, to tell you the truth I cannot remember the bearing specs except that it was a roller bearing my first impulse was tapered roller and first impulses are usually correct, but the more it was discussed the more doubt I had about the...
  7. LaffeyDD724

    300 HP GE motor

    Keith, just after I made the last post I got to thinking that I may be wrong on the tapered part of the roller bearing but it definitely would have to be a roller bearing, that much I am sure of. When I wrote my first post on this I was thinking tapered roller but now I am not sure about the...
  8. LaffeyDD724

    300 HP GE motor

    Keith, I cannot answer that question authortativly, so I won't try. I have always used a motor shop to change bearings on large motors unless it was a dire emergency. It has been a while since I have had to confront this type of problem, but to the best of my memory the work was done in the...
  9. LaffeyDD724

    300 HP GE motor

    Concerning the 300 HP press roll motor loosing opposite shaft end bearings. I have had some experience with loosing opposite shaft end bearings. Electric motor applications with belted load transmission require a tapered cone roller bearing on the shaft end, other wise the side loading will...
  10. LaffeyDD724

    Solenoid issue..

    Bravo, superb and magnificent, great job. Looks like a factory made item and performs like one also. Keith, I salute you, you are true to the electrical arts and definitely have the go getter sprit. You have sucessfully climbed this mountain and now await another daunting challenge. A+ Tom...
  11. LaffeyDD724

    Getting power from transmision lines electromagnetic field

    Such a practice is unlawful in the USA, I would be hesitant to consider such a practice considering it may be against the law and concidering the negative safety aspects of it as well. Tom None of us is as smart as all of us.
  12. LaffeyDD724

    Generator Relay Burning Out

    whycliffrussell, It seems that from your description of what is taking place, that the K1 contacts are overloaded for their rating. Having said that and not being familiar with the machine and not having access to it for trouble analysis and not knowing the maintenance history of it and not...
  13. LaffeyDD724

    help slowing down electric motor

    Hey, guys I have found something that looks promising, take a look at it and see if it has merit for this application. Check the URL http://www.anaconsystems.com/text/opti_e2.html Tom None of us is as smart as all of us.
  14. LaffeyDD724

    3 phase motor monitoring

    Thanks Scotty, I thought that I had goofed. Tom None of us is as smart as all of us.
  15. LaffeyDD724

    help slowing down electric motor

    Looks like you might need to go to France and use 50 Hertz current to make your bread. Tom None of us is as smart as all of us.
  16. LaffeyDD724

    help slowing down electric motor

    Looks like the supply voltage frequency might be the key. The motor data says that it will run 300 rpm slower on 50 Hertz. Now what could be done to lower the supply voltage frequency? Maybe you could put together some sort of electronic gadget to to drop the supply voltage frequency. Tom None...
  17. LaffeyDD724

    AC current sensing

    Checonbill, you may find what you need at this website try this URL. http://www.loadcontrols.com/products/products.html Tom None of us is as smart as all of us.
  18. LaffeyDD724

    3 phase motor monitoring

    Just copy and paste the url in the address bar and it will work. I tried it and it is OK I must not have hi-lighted all of it when it was copied. Tom None of us is as smart as all of us.
  19. LaffeyDD724

    3 phase motor monitoring

    I will try this again here is the URL. http://www.squared.com/us/products/relays_timers.nsf/unid/D19099054747188A85256CB60056D979/$file/phaselossrelays.htm Tom None of us is as smart as all of us.
  20. LaffeyDD724

    3 phase motor monitoring

    Check out this URL and see if these devices will help solve your phase loss concerns. (Single phasing) They appear to be very economical. http://www.squared.com/us/products/relays_timers.nsf/unid/D19099054747188A85256CB60056D979/$file/phaselossrelays.htm Tom None of us is as smart as all of us.
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