Now, I have a semi solid(or so Id like to think) grasp of power factor and how it applies to single and 3-phase systems. But in the case of a split phase supply, Im a little lost as to where the PF measurements need to be taken and the PF correction components placed...

Considering a typical split phase supply of the following type:

I understand that the voltage waveforms of each leg-to-neutral "phase" are, in fact, really in-phase with one another... and thus additive in nature. Which is why a measurement from one hot leg to the other results in twice the leg-to-neutral voltages. Etc, etc.

Where I need clarification is in regards to the following:

The way I understand it, we can find the reactive power consumed by the appliances on each leg of the split phase supply the good ol fashioned way: Q = sqrt[(VI)^2 - S^2] ... calculate Q for L1-to-neutral and L2-to-neutral.

Im guessing we also need to calculate the reactive power of the L1-to-L2 "phase" for the 240V appliances, right?

If I am on the right path here, we would have 3 reactive power measurements: Q1N, Q2N, and Q12. And summing these 3 measurements would give us the total reactive power that needs to be corrected for to improve the power factor, correct?

In regards to the actual power factor correction... say we are dealing with an overall inductive load that we will correct via placement of a parallel capacitor/capacitor bank. Where would this capacitor bank be placed? Obviously in parallel with the aggregate household load... but would that be across L1 and L2? Or do all 3 "phases" of the split phase supply need to have their own capacitors for correction?

Note: I do understand that using the term "phase" when discussing a split-phase supply is actually a bit of a misnomer...

Thanks for any insight you can provide!