Researching electric conversion of 15.5 G keg...250 V

[shatenfreude]

So I'm looking into converting my keg into an electric boiler as I get nervous using propane and it's cold as fuck over the winter here in NY. While researching I find people talking about 220 and 240 v outlets but I have a 250 v 30 amp outlet that used to be used for a dryer. Is this outlet suitable for use with a 5500w element?

The outlet looks exactly like this one with a slightly larger center hole: http://www.myrv.us/electric/img/N%2010- ... 0-volt.jpg" onclick="window.open(this.href);return false;" rel="nofollow

Does anyone have experience utilizing a similar setup for all electric runs? Thanks for any advice in advance.