Generally, the transformer can be loaded to 1000 voltamperes {1kVA} at it’s rated voltage and frequency, regardless of power factor. The transformer could be seen as “transparent” to power factor, but limited by a maximum voltampere load.
It’s a little confusing to discuss only watts and power factor. Voltamperes and power factor is easier to understand. As described, the 80%PF load could not be greater than 800 watts...that is still 1000 voltamperes, so the transformer is not yet overloaded.
In basic terms, because PF represents sort of an electrical efficiency, the closer to 100% or 1.0, the lower the circuit losses.
[This message has been edited by Bjarney (edited 05-23-2003).]
