If it's inside the fridge, with your line length and elevation to the faucets, it only needs to be set at about 8 psi. Turn off the gas to the kegs, bleed the pressure from the kegs. Then do what a10t2 says, but only turn it up to 8 psi. Trust me, with the gas in the fridge 10-15 is WAY too much. Your beer will still probably be overcarbed and pour really fast, but it will equalize in a few days.
I just noticed that you want to carb up to 2.5 volumes. That's high to me, but if it's a certain style I understand. If you're carbing higher it's naturally going to fly out of the faucet, unless you invest in some flow control for highly carbonated beers. The fridge temp is part of the issue too. 33 degrees for the beer will make it carb more, and the gas that cold will also put more Co2 in it.
Check this out too: http://www.tastybrew.com/calculators/carbonation.html
Calculate what volumes you want, then I would deduct about 2 psi, since your gas is in the fridge. Hope this helps. Nothing worse than pouring a glass of foam!