The PSU has a mains fuse in it and its outputs have over current protection. You don't find any other fuses in a PC.
Fuses give limited protection for electronics, they mainly prevent wires from burning. You could add a 5A fuse inline with the 12V connection to the ribbon cable if you are worried but if the wiring is done correctly there isn't really any risk of a short circuit or overcurrent. The bed wiring is thick enough to shut down the PSU in the event of a short and the current in the stepper wiring is limited by the driver chips. They would probably shutdown or blow up before tripping a fuse or burning wires.
Edited 1 time(s). Last edit at 11/25/2013 01:29PM by nophead.
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