Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. mpparent

    How are UPS SC Contributions estimated?

    Here...try this link: https://www.vertiv.com/49f28b/globalassets/products/critical-power/uninterruptible-power-supplies-ups/liebert-nxl-operation-and-maintenance-manual_00.pdf Page 57... Mike Mike
  2. mpparent

    Help Identifying Correct Classification of Haz Loc Electric Motor

    Old motor nameplates, I believe, were Div 1 capable (going by memory, so double check me on that). However, as described previously, check w/ your process engineer to ensure Group D is still applicable. Often-times in the plant where I worked, process chemicals were changed routinely and motor...
  3. mpparent

    X/R ratio of MCBs

    Hi cuky... Noted. However, I think the OP was referring to LV breakers. While the standard is old, the testing X/Rs haven't changed to my knowledge. Mike Mike
  4. mpparent

    X/R ratio of MCBs

    Screenshot from IEEE 551: Mike
  5. mpparent

    X/R

    IEEE C37.010-1999 gives: 1) Low value ~9 2) Medium value ~19 3) High value ~25 Mike Mike
  6. mpparent

    single phase service to 3-phase motor startup procedure

    This site has some good information: https://www.northamericaphaseconverters.com/resources-assistance/rotary-phase-converter-faq/ Mike Mike
  7. mpparent

    single phase service to 3-phase motor startup procedure

    Thanks Keith...learn something new every day. Mike Mike
  8. mpparent

    Material of Construction for Electrical Panels

    Do you have a specific application? Mike Mike
  9. mpparent

    Instantaneous trip elements

    Potential cable/wiring withstand issues... Mike Mike
  10. mpparent

    Bus Duct Seperation of Normal and Emergency Power?

    Well, IEEE 493 may provide some insight. Failure rates for bus duct is .0003 failures/yr. Mike Mike
  11. mpparent

    Power Factor Correction Design

    Often-times if you ask, the manufacturer's have the harmonic spectrum for their drives. Can you model the system using SKM, Easypower, etc. and see what the overall harmonic spectrum is? That should get you fairly close. Also, IEEE 519, IMHO, is often misapplied. Furthermore, I have seen current...
  12. mpparent

    2 Years Sober, and New to Variable Frequency Drives (VFDs)

    It's also good to periodically check-in with your customers. Tell them about new tech, etc. A little face time goes a long way. Mike Mike
  13. mpparent

    Monitoring VFD on ??HP motor

    Incidentally, We were reading unbalanced currents on both the line and load sides of the VFD. That can't be good... (I'm not sure of the % of unbalance. I'll know more in a couple of weeks...the monitoring period) Mike
  14. mpparent

    Monitoring VFD on ??HP motor

    waross, The process owner really isn't sure if the existing motor is adequate. Else, we would have certainly done that. Mike
  15. mpparent

    Monitoring VFD on ??HP motor

    All, I have a motor (of which I do not have a nameplate to verify HP rating), which belongs to a process. The process owner wants to purchase a new motor, but with no nameplate, we are unsure of what to purchase (a new motor was purchased at one point and it turned out to be wrong). The motor...
  16. mpparent

    Replacing MCC Feeder Cables

    What about putting a camera down there to assess the condition of the pipe? Mike Mike
  17. mpparent

    Hazardous Equipment Selection References

    Jerry, I have the NEC, I just wondered if there were any specific references I could consult. Mike
  18. mpparent

    Hazardous Equipment Selection References

    Hi All, Can anyone recommend some good references for the subject line topic? I'm mostly thinking about motor selection, but any references are appreciated. Thanks, Mike Mike
  19. mpparent

    Low Voltage Motor Rewinding/Testing

    Thanks... Mike Mike
  20. mpparent

    Low Voltage Motor Rewinding/Testing

    Hi All, I'd like to get some feedback on what others have done in regards to the rebuilding/rewinding of motors, sizes 25HP and above. In my opinion, meggering is not that great a test. Are there any other tests you all do? Do you even bother rebuilding motors of this size? In my former...

Part and Inventory Search

Back
Top