AutoTransformer Question

[a4u2fear]

Ideal 25kVA 480/120V 1PH transformer is to be used as an autotransformer supplying load from a 480V source

If it is in Buck mode, and the coils are carrying rated current, the max KVA load the transformer can accomodate is?

75kVA answer

I came up with 100kVA

Is somehow "coils carrying rated current" the key?  Or is the answer a mistake?

 

[munyua44]

the current might have been caused by voltage serge ... that rating of 100 KVA is ok because it is within the range of what the transformer can handle

 

[salmanshu322]

It means actual winding power handling capacity is only 1015 KVA but this autotransformer can handle 5000 KVA means auto transformer can handle 5 times more power and 5 times smaller than a conventional 2 winding transformer

 

[Zach Stone P.E.]

Ideal 25kVA 480/120V 1PH transformer is to be used as an autotransformer supplying load from a 480V source

If it is in Buck mode, and the coils are carrying rated current, the max KVA load the transformer can accomodate is?

75kVA answer

I came up with 100kVA

Is somehow "coils carrying rated current" the key? Or is the answer a mistake?

Three 25 kVA single-phase transformers connected together to serve a three-phase load will be able to supply a total of 75 KVA. Each individual transformer is supplying 25 kVA.