It should be a regular power cable, but your circuit breaker (
http://electronics.howstuffworks.com/circuit-breaker.htm) is the thing you need to keep an eye on.
A standard household circuit that gets distributed to one or more rooms (sets of outlets connected to one of the circuits) is normally 20 amps (2000 watts) and is written/printed on the switch on the circuit in the breaker box (
http://www.homedepot.com/catalog/productImages/300/e6/e693993f-67ed-4fb0-9ab9-8b90c01881c2_300.jpg)
Running a 30 amp hashing system on a 20 amp circuit will probably blow the circuit as soon as it gets going. If you underclock it to use less power you could probably get it under 20, but you bought 30 amps worth of hashing power.
Bigger circuits are set up for rooms with needs for more power, like laundry room or kitchen. You can add or replace circuits with beefier ones, but you should hire an electrician to do this if you don't know what you are getting into. If you choose to do it yourself, just make sure to turn off the power so you don't kill yourself.
Good luck!
