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!

Recent content by raar

  1. raar

    What is a Package Starter (PS)?

    Thank you for replies @waross and @jraef, I suppose the abbreviation makes sense, but not overly helpful.
  2. raar

    What is a Package Starter (PS)?

    Hi, i've recently stumbled across a drawing set that includes mechanical schedules with motor starting types and some include the "PS" abbreviation. Looking at the abbreviation page that stands for package starter. I have basic familiarity with VFD, electronic soft starters, auto-XFMR, WYE-DELTA...
  3. raar

    (AR Hileman) Insulation Coordination for Power Systems Appendix Files

    I bought a copy of this book recently, and it contains an Appendix titled "Computer Programs for this Book" which were apparently provided on multiple disks at one point. These were DOS programs created by the Author that I wanted to attempt to use with https://www.dosbox.com/ to accompany...
  4. raar

    Determine positive sequence Zpt, Zst from transformer test report (with buried delta tertiary)

    Per the report the phase relationship is YNyn0+d1. As bacon4life mentioned the report lists identical ratings for the high voltage and low voltage connections. Unfortunately I do not own the report, it is not mine to share so I shouldn't upload a copy, and understand that makes things more...
  5. raar

    Determine positive sequence Zpt, Zst from transformer test report (with buried delta tertiary)

    Hi prc, thank you for the response, that is interesting. I have access to study where a similar transformer is modeled, but the positive to zero sequences are: |Zps1| ~= 1.007 * |Zps0| |Zpt1| ~= 1.312 * |Zpt0| |Zst1| ~= 0.141 * |Zst0| The above relationships seem generally consistent with...
  6. raar

    Determine positive sequence Zpt, Zst from transformer test report (with buried delta tertiary)

    This is my first experience with a Wye-Gnd to Wye-Gnd transformer with a internal grounded delta tertiary winding (no external terminals available for connection). I am trying to model this transformer for short circuit, load flow, downstream arc flash and it seems most modeling software...
  7. raar

    VSD Supply Transformer Selection

    Thanks again everyone for the replies. I did look at the K-rated Eaton's, the smallest they had in a single can is 9kVA, and the secondary voltage would be at 208 VAC line to line. Originally I was leaning towards a 208Y/120 VAC since that provides an 8 volt margin to the minimum drive...
  8. raar

    VSD Supply Transformer Selection

    Thank you for the quick reply @itsmoked. 1) Yes the motor is 3-phase, however the drive specs list 3-phase input as a requirement. 2) Understand, there are some controls loads, however I believe the small motor load is still larger. The controls are still WIP due to some problems found...
  9. raar

    Synchronous generator field tests

    Not sure what types of generators you have, but here are some others that may be appropriate. Lubricant or fuel analysis Bearing temperature Infrared thermography Polarization Index Measurement of coast down time Borescope / visual inspection
  10. raar

    VSD Supply Transformer Selection

    Have a grinder machine with an approximately 1HP motor with a Mitsubishi Model FR-D720-1.5K drive. Per the machine manual (English), the product requires 230 VAC, 3-Phase, 3-wire, 60Hz and appears to be originally designed to IEC standards, but also sold in North America. We've already had a...
  11. raar

    Unit Conversion (Vibration - micro in./s TO mm/s RMS)

    I'm not fully confident in this response because my quick calculator conversions result in: 77 dBV -> ~0.180 mm/sec and 83 dBV -> ~0.360 mm/sec vice the results they provide as equivalents. This may be due to rounding or decimal places though. The only 77 I see in the image above is the total...
  12. raar

    Shop Balancing Machine Questions - Sensitivity Unit Conversion & Determing Achievable Unbalance

    @electricpete thank you for taking the time to work through the two questions and provide confirmation. I've bookmarked that smath tool, that is the first time i've seen it, pretty nice. @GregLocock thank you for the confirmation as well.
  13. raar

    Shop Balancing Machine Questions - Sensitivity Unit Conversion & Determing Achievable Unbalance

    @GregLocock, I'm not sure, it's possible they made a mistake, I just thought it more likely that I did. In the 2nd question I mentioned rotor weight because we primarily deal with rotor and impeller balancing, but I suppose I should have written rotational part or assembly weight.
  14. raar

    Shop Balancing Machine Questions - Sensitivity Unit Conversion & Determing Achievable Unbalance

    Hi everyone, I'd appreciate some assistance with the following two questions, I do not have much experience with balancing machines. I'm attempting to convert a balancing machine sensitivity specification from g-mm/kg to Imperial (USCS) units of oz-in/lb. I've used the following conversion...
See more

Part and Inventory Search

Back
Top