Need help finding a transformer

Thread Starter

Sprayman

Joined Mar 31, 2020
8
Hi all I am new to the world of transformers. I was asked to find a transformer to go from 3 Phase 200VAC to single phase 230VAC at 50/Hz. It should be capable of about 1kVA.

Im not quite sure where to start. here is the info i was given.


  • 1/N/PE AC 230V 50Hz
  • 3/N/PE AC 200V 50Hz

From what it looks like. Our system currently runs on single phase and we will be powered from 3 phase.

Any help would be lovely, again a tad new to all this!

Thank you!
 

MaxHeadRoom

Joined Jul 18, 2013
21,636
If going to 1phase from a 3phase source, you only need a 1ph to 1ph transformer, you would not use a 3ph to 1ph, as it would be pointless.
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
21,636
I am curious to see how you wire a 1phase transformer to 3ph, generally the usual, common way, is to connect the primary to 2 phases, which is 1ph to 1ph.!
A 3ph transformer is simply three 1ph transformers on the same frame.
Also is the transformer in question, star or delta output connected?
Max.
 

Thread Starter

Sprayman

Joined Mar 31, 2020
8
If going to 1phase from a 3phase source, you only need a 1ph to 1ph transformer, you would not use a 3ph to 1ph, as it would be pointless.
Max.
Im a little confused. I have been seeing that an easy way to go from 3ph to 1 ph is to only connect 1 ph from my 3ph output. But what you are saying is similar i think? If i understand right youre saying only connect one wire from my 3 Ph source to the transformer effectivley making it a single phase coming in. and then it would just be a matter of stepping that up?

My only quesiton about that is do I lose my 200V input? or so i need to adjust my transformer since its only 1 wire being connected instead of all 3? (Does the input voltage drop with only 1 wire connected?)
 

MaxHeadRoom

Joined Jul 18, 2013
21,636
State the phase to phase voltage and if it has a star connected secondary on the supply TFR.
You either connect across two phases, which is essentially single phase, or use one phase to a star neutral.
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
21,636
Yes those are typical 1ph - 1ph control transformers.
I am assuming that the source is 200v phase to phase?
Which is a little oddball, would give you 115v phase to (N)eutral.
If the source is 200v ph-ph then the closest primary for the one shown is 208v.
Max.
 

Thread Starter

Sprayman

Joined Mar 31, 2020
8
Yes those are typical 1ph - 1ph control transformers.
I am assuming that the source is 200v phase to phase?
Which is a little oddball, would give you 115v phase to (N)eutral.
If the source is 200v ph-ph then the closest primary for the one shown is 208v.
Max.
That is past the info i got, so we shall see. If ph-ph is more standard then i would assume yes. Love learning new stuff like this! I will report after sending this over to the head honchos (This is really hard seeing as how i came from a company that did a lot of chemisty work and everything i saw that said ph was pH and not phase :p)
 

MaxHeadRoom

Joined Jul 18, 2013
21,636
Hi all I am new to the world of transformers. I was asked to find a transformer to go from 3 Phase 200VAC to single phase 230VAC at 50/Hz. It should be capable of about 1kVA.
Just a little curious as to why someone by their own admission is "new to the world of transformers" would be selected to find one?;)
What is the application?
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
21,636
Other questions come to mind.
Who will be applying the new transformer?
Is an isolated supply needed, or will there need to be a reference to earth GND, IOW a neutral?
Max.
 
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