Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

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

Search results for query: *

  • Users: PNA
  • Order by date
  1. PNA

    using 2 legs of 208 3 ph to supply a VFD 120 vac 1ph input and 230 v output...

    I give up.... The facility's power supply. In today's power-hungry society, it's getting hard to obtain a good source of clean non-distorted power. Over and under voltage conditions greater than plus-or-minus 10% will trip most drives. A voltage unbalance between phases of 3% to 5% can cause...
  2. PNA

    using 2 legs of 208 3 ph to supply a VFD 120 vac 1ph input and 230 v output...

    230 single phase.....each phase is in line with other 208 three phase.....each phase is 120 degrees apart yes you do get 120 vac from line to neutral however: phasing differences can cause issues in some cases.... there are still many older existing facilities that have configurations that...
  3. PNA

    using 2 legs of 208 3 ph to supply a VFD 120 vac 1ph input and 230 v output...

    Bill, Please read carefully.... I have a VFD that is a 120 VAC 1PH input. I have attached a spec sheet. It provides 230 VAC 3PH output. We have sold hundreds and hundreds of these units. My question is not the availability of certain voltages etc..... I have been in design for the last 15...
  4. PNA

    using 2 legs of 208 3 ph to supply a VFD 120 vac 1ph input and 230 v output...

    4 wire indicates ground, neutral, 2 hots single phase: i.e. supplied to a house black to neutral - 115 vac > VFD in > "230 vac out" (motor is rated for 230 vac) red to neutral - 115 vac > VFD in > "230 vac out" (motor is rated for 230 vac) 2 "separate circuits" so from what i have read, 208 -...
  5. PNA

    using 2 legs of 208 3 ph to supply a VFD 120 vac 1ph input and 230 v output...

    We have had motor and or vfd failures when customers use 2 legs of a 208 vac 3 phase system to supply our machines.... we state 230 single phase 4 wire I know there are phase issues, etc but trying to explain that to my bosses is difficult.... Help?
  6. PNA

    theroretical calculation of acfm of a radial blade fan

    hmmmm....if i had a few grand or better, i would just run out and buy that instead...thanks anyways
  7. PNA

    theroretical calculation of acfm of a radial blade fan

    thanks, but its more to do with axial fans which are very predictable from a design standpoint, where the centrifugal fan designs are not as much... i know there are efficiencies lost with various designs, sizes, speeds, etc, but there must be a way to calculate ideal air flow based on a...
  8. PNA

    theroretical calculation of acfm of a radial blade fan

    with knowing blade thickness, inner and outer diameter, it has a back support, depth of blade is known any ideas thanks paul
  9. PNA

    natural gas 2" pipe 10 psi

    a few years ago i specified a 3" connection on a 3" manifold, to supply 5,000,000 btu's of natural gas, it worked beautifully
  10. PNA

    natural gas 2" pipe 10 psi

    i dont think a 3" line is going to happen
  11. PNA

    natural gas 2" pipe 10 psi

    that is a big concern, and yes you are correct, $$$$$ are involved. if i was the contractor, and i knew i had to replace the whole length of supply back to wherever it goes, and neglected to quote that or do that prior to installation? that would get messy
  12. PNA

    natural gas 2" pipe 10 psi

    I understand that and hopefully a resolution will come sooner than later, and all the info will eventually be "found" out Paul
  13. PNA

    natural gas 2" pipe 10 psi

    If i can provide eng info contrary to what the contractor is claiming will work, i will do so. End of story.
  14. PNA

    natural gas 2" pipe 10 psi

    Main issue, is the customer wants they're furnace running properly, we provided detailed info on what was required for utilities and the contractor is doing a lot of finger pointing. So commissioning delays may have penalties.
  15. PNA

    natural gas 2" pipe 10 psi

    Wow! Mine is 3/4 from the meter
  16. PNA

    natural gas 2" pipe 10 psi

    was that on a 1/2" or 3/4" supply?
  17. PNA

    natural gas 2" pipe 10 psi

    Agreed! Would that not be up to the contractor doing the supply piping to calculate?
  18. PNA

    natural gas 2" pipe 10 psi

    One thing i have learned over the years, is that "SHOULD WORK" doesnt explain to my bosses why it doesnt work.
  19. PNA

    natural gas 2" pipe 10 psi

    As far as what was there before the furnace was installed? I have no idea what chart, actual pressure, etc. Visible piping twists and turns like crazy, then goes through a roof and disappears somewhere...
Back
Top