# Wire size of step up 1.6 KVA power transformer

1. ## Wire size of step up 1.6 KVA power transformer

I am designing a step up transformer. I have calculated all the calculation as like core area, turn per volt, P volt, S volt. All is okay. But now I need the right wire size according to my load current.

Transformer Details:

Primar volt: 130v
Secondary volt: 200v
Imax: 8A (so 8x200= 1.6KVA)
Core area: 3x2=6inch
Core type: EI
trurn/volt: 1.16v
P turn: 150t
S turn: 232t

So now, what size or SWG of copper wire should I use for 8A?

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2. ## Re: Wire size of step up 1.6 KVA power transformer

Any reason you designed an isolation transformer rather than an auto transformer? You can safe 65% of transformer power.

I presume, you have chosen the core size from a transformer design table. It should also have a specification for winding current density respectively available winding window, choose wire gauge respectively.

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3. ## Re: Wire size of step up 1.6 KVA power transformer

Originally Posted by FvM
Any reason you designed an isolation transformer rather than an auto transformer? You can safe 65% of transformer power.
Thanks, but I do not need auto transformer.
On the other hand, I have collected all these equations from some online blog helped by google. But there was no information or data about current rating or wire size, and I have created a transformer practically using 18swg, and voltage was perfect as i needed.

Now, I am confused that 18swg is enough for 8A or not ? If not then what should be ?

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4. ## Re: Wire size of step up 1.6 KVA power transformer

Hi,

An autotransformer is smaller, smaller core less copper, but has no isolation....it's just to reduce site and cost.

Maybe you can go through this: https://www.electronics-tutorials.ws...er-basics.html

One approach is:
If you want a secondary winding loss if 1% full power....(as an example)
This is 1% of 1600VA --> 16W.
At 8A this means: R_copper = P/(I x I)= 250mOhms

Now with the number_of_turns, the average_length_per_turn and the specific_resistance_of_copper --> you are able to calculate the diameter.
(Ignoring proximity effect, skin effect and temperature rise)

Klaus

5. ## Re: Wire size of step up 1.6 KVA power transformer

Now, I am confused that 18swg is enough for 8A or not ?
It's not. Current density for 1.6 kVA transformer (e.g. EI 195c) should be below 1.5 A/mm².

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