Transformer

[debco99]

Im using a 15 kva 440 vac pri. 400 vac sec. Y transformer in a 3 phase servo drive application do I need to be concerned about K factor?? Thanks in advance (trans center tapped to ground)

 

[Skogsgurra]

It depends a lot on how much current you draw. If you current is well below the transformer rated output current, then do not bother. If you are close to rated current and if your load is continuous (not likely with a servo), then you should consider the effects of the bad curve form that servos usually have.

I would say that you probably do not have to worry. Especially if your servo is working intermittently and takes less than transformer rated current.

 

[maged541946]

It depends on the type of load as mostly the source is clean. If the application is electronics then it may have a lot of harminics generated due to rectifier input circuit.

You did not mention is it an isolation transformer or just an auto transformer regulator.
If it is just an auto, this means the load is really large and posibility of harmonic generation in less likely but if if there is a seperate primary/secondary coils, all those have to go through the iron core and you may worry about harmonics generated.

Please note the difference between auto transformers and primary/secoundary transformers.
In auto most of the power pass directly from input to output and the transformer need to only compensate for difference, so with 440/400 volt rating you may actually need

(440-400)/440 or 1:11 th the power of a primary secondary transformer with the same voltage ratio