single to 3 phase conversion for delicate equipment ?

[Alphatronique]

Hi

i finally broke the bank and buy a top of the line  "almost" new pick & place machine  O0   

so now i have on shop only 120 and 240 v single phase supply  120  was phase neutral  and 240 was  phase / phase   

then i need 208 3-phase  2.2kva  / phase  (1.8KVA average )

so  for now i have reject

rotary phase converter                , lack of balance  and not like wide variable load  specially at machine idel whit light load
phaseperfect  digital converter    ,  to mutch expensive  and 2 phase pass troug it and generate the third one whit PWM  so 180 deg + 180 deg + ?   not 120 deg phase  ,still need 10kva transfomer
bring  3 phase to the house        , local utility power compagnie not like idea to bring commercial 3 phase into a residential house and only supply it 600volt  and not what 600 volt on my house 
Scott-T transformers                  , not understand well how it work  and some said it work some saidit not work in north america singes phase   
hack power supply of machine    , MyData will refuse to service it one modified  ,and that kind of baby need some support someday  (line scan  camera  , linear motor and so on ....  )

so any idea or suggestion ?

[Kleinstein]

A rotary converter should be the cleanest solution. It depends how well they can handle varying loads, but some can do that quite well. It may have to be a little larger, like 7,5 kVA oder 9 kVA. The main downside is that it produces some acoustic noise and the voltage may not be very stable. Installation is something for a qualified electrician anyway.

The 600 V are not such a big problem - this just needs a separate local transformer. Typical the unit can be well enclosed, so safety is not a problem. Using weak existing lines up to there maximum current rating is the larger danger. Usually more people die from fire caused by overheating electric systems due to high current than from electrocution  - so the American 110 V is more dangerous than the European / Australian 230/240 volts.

[Alphatronique]

Hi

whit 600V   it more think about re-sale of the house later  ,and redo power entry was not so cheap
and usually my local electric company not install 3-phase on residential  aera

probably that will end-up whit hack the machine even if not really like that option

[NiHaoMike]

A surplus VFD plus some LC filters to smooth out the output?

[Ian.M]

I was thinking motor-generator set.  Take the three phase alternator head off a genset with a wrecked engine and couple it to a beefy induction motor.  Add a VFD on the input if you need accurate frequency control, otherwise a single phase motor or static phase converter would do if you don't mind the output frequency being low by the slip percentage.

[calexanian]

Typically one would use a flywheel system with a rotary phase converter. Otherwise ask the manufacturer of the machine for a recommendation.

[Psi]

Could find a 2ndhand 3phase industrial UPS from like a datacenter.
Then hack it to always run on battery and find a powerful single phase PSU to float charge the batteries.

Or, you could always modify your machine to run on single phase power but do so in such a way that it's easy to return to factory spec without any evidence you modified it.
Obviously you would have to avoid any onsite support visits since its not usable once returned to 3phase mode.

[jeff.remus]

Yet another was is with an LVG or line voltage generator. The work similar to audio amplifiers one channel per phase.  Aetechron.com

[Alphatronique]

Hi

"Otherwise ask the manufacturer of the machine for a recommendation"     -->  company was not cooperative  at all on it used machine until you paid ,training ,registration and installation so 10,000$ ,then maby it help or not 

as for UPS until now all that i see was terrible expensive ans 3 phase in 3 phase out , and phase perfect  digital phase converter + tranfo may cost less effective @ ~5000$ ,bit still quite expensive

"A surplus VFD plus some LC filters to smooth out the output"  -->  make sense but most VFD have motor start-up sheme build in that bit afraid me of how it may react to machine operation
that not ack like a induction motor at all  , i not yet fin a plain drive whit not ton of fancy option that may screw-up  the thing

http://aetechron.com/   that great no knot that company  ,but honestly a 10kva system was for sure not cheap at all ;-)

 

[jeff.remus]

Just to help balance the load there are balance transformers and capacitors that are used on grid tie photo voltaic power inverters. I have them in my zantrax PV45 but I have not measured there performance.  I have seen the balance transformers on YouTube. If you have an osciloscope take a look at the three voltages and then the three current clamps to see what is really going on first before you spend any money.

[nitro2k01]

Hi

i finally broke the bank and buy a top of the line  "almost" new pick & place machine  O0   

so now i have on shop only 120 and 240 v single phase supply  120  was phase neutral  and 240 was  phase / phase   

then i need 208 3-phase  2.2kva  / phase  (1.8KVA average )

so  for now i have reject

rotary phase converter                , lack of balance  and not like wide variable load  specially at machine idel whit light load
phaseperfect  digital converter    ,  to mutch expensive  and 2 phase pass troug it and generate the third one whit PWM  so 180 deg + 180 deg + ?   not 120 deg phase  ,still need 10kva transfomer
bring  3 phase to the house        , local utility power compagnie not like idea to bring commercial 3 phase into a residential house and only supply it 600volt  and not what 600 volt on my house 
Scott-T transformers                  , not understand well how it work  and some said it work some saidit not work in north america singes phase   
hack power supply of machine    , MyData will refuse to service it one modified  ,and that kind of baby need some support someday  (line scan  camera  , linear motor and so on ....  )

so any idea or suggestion ?

A bit OT, but how did the formatting of the post end up this crazy way?

[mikeselectricstuff]

It might be worth looking at exactly what the 3-phase supply is going into - it may be the case that it's going into switchmode PSUs, in which case you may be able to run it from a higher voltage single phase supply (or maybe DC) , or replace the PSUs with single phase ones.

It could simply be that the only reason it's 3-phase is that's what most of their customers have in their factory, rather than actually needing it to be 3-phase for a technical reason..

[DanielS]

If the machine's power supply is simply a 3-phase to DC converter with diodes dumping line voltage across a single input cap bank, you should not need to lose sleep about having perfect conversion. You could have a 300V_DC supply connected to a single pair and the supply's rectifier would most likely be fine with 8A_DC. Of course, you would need to open the supply to verify how it is designed and the input components' ratings before doing this.

Unless the power supply also has power factor correction, you should not need more than a simple modified square wave driver to run its three phase input if you insist on spreading the load across all input diodes.

BTW, one of the big benefits of 3-phase power is achieving better than 10% ripple before adding any filtering caps. You may need quite a few caps to get single-phase ripple that low.

[amyk]

It might be worth looking at exactly what the 3-phase supply is going into - it may be the case that it's going into switchmode PSUs, in which case you may be able to run it from a higher voltage single phase supply (or maybe DC) , or replace the PSUs with single phase ones.

It could simply be that the only reason it's 3-phase is that's what most of their customers have in their factory, rather than actually needing it to be 3-phase for a technical reason..

That's what I was thinking too - 3-phase is usually necessary because it's being used to power large continuously rotating induction motors, of the sort used in CNCs and lathes. A P&P doesn't seem to me like it'd have such a motor, although the 3-phase supply might be more due to high power consumption.

[cosmicray]

still need 10kva transfomer bring  3 phase to the house, local utility power compagnie not like idea to bring commercial 3 phase into a residential house and only supply it 600volt  and not what 600 volt on my house 

Do the utility lines on your street even have 3 phase available ? When I live, there is a single 10kV line to a transformer on a pole.

[Towger]

Ask per Mike and Co.  What in the machine actually needs a 3 phase supply? Do you have documentation or the actual machine yet.  It may not require much to convert to single phase.