"Paul Mathews"

Transformer VA rating could be considerably
less than the wattage of your load, since power ratings would be
effectively higher at 400Hz (compared to their 50 or 60Hz VA rating
frequency).



** The VA rating at 400 Hz will be virtually the same as at 50/60 Hz. The
magnetising current in the primary will reduce at the higher operating
frequency but since this is a small fraction of the rated current ( indeed
small for a toroidal) there is not much overall change.




.............. Phil