3 phase Vs 1 Phase Transformer Cost

[I_am_learning]

I have just completed a course in Transformer Design. But I am now surprised at a result I found. For Handling Same Power (Say 15 Kva) at around same efficiency, 3 phase transformer are more heavier and costlier than single phase transformer.

Although, The Copper Weight Decreases in case of 3-phase, its benifit is nullified by much more increase in Iron Weight. Although the Cost Ratios might be affected by market economies of Copper Vs Iron, The weight ratio will be same.

I just want to hear if some of you are already aware of this OR my calculations are madly flawed!

 

[Carl Pugh]

I agree.

For the same KVA a 3-phase transformer is heavier and costlier than a single phase transformer.

For the same KVA, three single phase transformers are heavier and costlier than a 3-phase transformer.

 

[I_am_learning]

Thanks.
Doesn't that sound absurd to you that Transmission in 3 phase is cheaper but Transformation is expensive?

(Sorry for late reply)