Recent content by PNA

someone close this thread....please....

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...

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...

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 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 -...

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?

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

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...

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

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

i dont think a 3" line is going to happen

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

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

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

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.