Input protection on a DC jack
It's a really bad idea to use a standard connector type for a non-standard purpose, especially if the consequence of connecting a standard cable (i.e. AC mains) to your nonstandard equipment could be hazardous.

Wikipedia has a good overview of connectors typically used for DC power. As the article notes, 'barrel jack' connectors are usually only rated for a few amps, although they are seen on laptop power supplies at higher currents. 

Out of the choices in the Wikipedia article I would suggest you use a 4-pin XLR connector (chassis plug and line socket), wiring pins 1+2 negative and 3+4 positive as it describes. These are not too expensive if you look around, are rated for your required current and you would be using them in line with an existing standard.