Digital logic input with very wide input voltage range
You should be able to do this if you think of this input voltage as a analog signal.  Attenuate it by 100, and you have something in the 0-5 V range.  5 V in results in only 50 mV, but that is still plenty high enough to detect above any reasonable noise floor.

It might be a good idea to run this into a micro to actually measure the voltage, then have the code decide whether the input voltage is really "present" or not.  With such a 100:1 range, I expect it's not as simple as just checking whether it's over 4 V, for example, or not.  The code can hopefully check what the expected level is, perhaps see that it is fairly steady, or whatever.  Keep in mind that a line that is at 480 V when "on", might have more than 5 V of noise on it when off.  I think some logic that does more than just a dumb fixed threshold comparison will be useful.

Due to the high voltage, you want to use a high impedance divider else it will dissipate significant power.  1 M&Omega; top resistor and 10 k&Omega; bottom resistor sounds like it might work.  That's not quite 1/4 W at 480 V in, and of course much less at lower voltages.  It also provides 10 k&Omega; impedance output to drive the A/D input with.