Will this work? I just bought a EVGA 500w PSU and it came with a cord which says 125v but the psu is 120v-250v. My outlet is 240v. Is it safe to plug it in?
What do you mean the cord "says" 125V? Where does it say this?
....and if the cord is for 125V....what about the plug? Does it have the proper plug for your outlet?
If the outlet is anything other than an ITA type B (which it better be, and if it's an ITA type A, you're in serious trouble), you need to change the PSU line lead.
Wires don't 'care' about voltage.....it's the current. If anything, cords running half the current at twice the voltage are even better off..... (which is why many data centers use 208V) ANy power cord labeled '115/120V is often done so merely as reference to what connector is put on the end of it for part number/manufacturing purposes...