Power factor of a transformer at 80%

fred2028

PF is P / S in general. If the transformer is running at 80.1% of full load, the PF should stay the same right since

PF = 0.801P / 0.801S
= P / S

since if the transformer is running at 80.1% full load, the output S and output P would both be 80.1% right? So basically, no matter what load, the PF is constant since the percentage of full load of the transformer cancels out?

NascentOxygen

The power factor not being exactly unity is due to what, exactly?

I'm trying to understand this. The units of S , are they volt-amperes?

Is the load considered purely resistive in all of this?

What is the equivalent circuit model you are using for your power transformers? Does this give you a clue?

uart

Hi Fred. What percentage (of it's full load value) do you think the magnetizing current would be when the transformer is running at 80% load current?