# Buck Boost Transformer 380V 240V 3-Phase



## telsa (May 22, 2015)

vinnygalbo said:


> I have a machine that I built here in the US.
> 
> It has a couple of Panasonic servo motors and drives 240V three phase.
> 
> ...


The transform is too severe for a bucking autoformer.

Use a SINGLE LEG of 380 VAC power ( 219 VAC @ 50 Hz ) to feed your own VFD... to spit out 3-phase 240 VAC 60 Hz power.

Done.


----------



## oliquir (Jan 13, 2011)

do your vfd needs 3 phase input or only 1 phase?


----------



## varmit (Apr 19, 2009)

If the motors that the VFDs are controlling are small enough HP AND the 380 system has a neutral, you could use one phase and the neutral to supply a single phase ( about 220 VAC ) input/ three phase output VFD. You can also get servos that are single phase input and three phase output.

BUT: The physical size of single phase input/ three phase output will be larger. Some brands of VFDs will accept single or three phase input- BUT to operate on single phase, at the same HP output, will require upsizing the VFD a couple of sizes( Example: a 3 HP motor might require a 7.5 HP VFD when supplied with single phase.

Your most simple route would be to supply the machine with a 380 to 230, three phase transformer. There are even some, so called world transformers that have multiple taps for different voltages.


----------



## Wiresmith (Feb 9, 2013)

is it 50 Hz in china


----------



## Mike_kilroy (Sep 2, 2016)

vinnygalbo said:


> I have a machine that I built here in the US.
> 
> It has a couple of Panasonic servo motors and drives 240V three phase.
> 
> ...


Yes, buy one. Why not? Ur link did not work for me but most Panasonic servos are tiny, 100 watt or so.

Google should give u abt 3,000 mfgrers of the xfmr u want. My guess abt $400.00.

Being china, consider isolation xfmr instead for their crappy power. 
Cost will be almost identical - I know ours would be.

And u cannot use a vfd for this. Won't work for many reasons.

Sent from my SM-G900V using Tapatalk


----------

