Transformer core calculations

You could weigh it. Assuming 60Hz, single phase, if it's well made, at least 20 VA per pound; if cheaply made, more like 10 VA per pound. Sorry, national security prohibits me from doing VA per kg.

"national security prohibits me from doing VA per kg"

lol that just about tells me nothing...how do I determine if it was cheaply made ...lol heheψ

hello

i need calculation method for transformer core 5 kva .

An approx formulie for small transformers 50/60Hzis

VA=[A/116]²

Where A= CS area of center limb in Sq mm.

Hi Garth;

Interesting answer, but I don't know the meaning of the word "limb" in this context, could you please explain to me wether it refers to laminated core or winding, or both?

Also, what would be the correct imaginary cut, longitudinal or traverse?

Thank you

Yahlasit

In the case of an H style transformer this is the center lamination upon which the coil is wound, the cross sectional area of this is usualy twice that of the outer sections [limbs] and this is a transverse cut. U shped laminations have only one section..

I don't calculate but rather look at the listing and spec sheet from a local supplier to get the physical size then cross reference it to the VA rating as indicated. Close but not exact. Good question! this has also plagued me for years. Will keep an eye open on this particular forum thread.