Are you sure about this? The current in the hot wire must be the same as in the neutral wire, or there is a ground fault (and that would actually do the opposite, decrease neutral current). Three-phase might be different although I don’t see why it would (and how many computers and lights run on three-phase power, unless you mean a supercomputer). It is true though that low power factor increases current draw, although wires don’t have to be resized as long as you look at the current rating on the equipment and stay within the ratings; e.g. 15 amps/120v volts can handle 1,800 watts* or 1,800 VA (900 watts actual with a PF of 0.5, or 1,350 at 0.75 PF).
*Of course, you want to derate by 20% or so for continuous loads.
Unless you’ve got a big-assed inductive load or the panel is seriously unbalanced (loadwise), you should have no light dimming going on. You may see a flicker if, say, your heat pump kicks on. $3200 for a sub-panel? Yikes!
[QUOTE=Michael63129]
Three-phase might be different although I don’t see why it would (and how many computers and lights run on three-phase power, unless you mean a supercomputer).
[/QUOTE]
Yes, three phase is different. The issue isn’t one big computer*, but offices with hundreds of PCs and/or hundreds of fluorescents.
Three phase power is commonly used by large servers. Our new mainframes run on four 30-amp three phase power feeds per system, for example.