I just moved to Oviedo, Fl. I used the oven successfully to heat a plastic product before bending it in a pnumatically run molding jig. I was using my dryer outlet, however, the home I now live in uses gas for its dryer and oven. My main feeds eight 15 amp, ten 20 amp breakers, plus one 40 amp for my AC.(outside) They all read '10 AIR, OOO, 120/240 Vac. Do I need to put in a 200 amp main or can I just add another 40 amp breaker?

Not seeing any attachment.

You title is confusing,

"I need to run a 39 Vac"

And you don't clear it up in the post.

Your asking for a load calculation to be done, need the square footage of the livable space in the home, and a list of wattages or amps of all major electric appliances.

I suspect you can just add a 40 amp breaker, but need to know the load for that circuit, and the other information to confirm what is needed.