I ran across a chart that showed the maximum length of circuits. It claimed a maximum length of 50ft for a 120v, 20A circuit on 12 gauge wire.

I have a 120v, 20A circuit that is approx. 85 feet long, on 12/2 wire. It is used ONLY for a window AC unit that draws 5.6 amps.

Does the amperage draw of the appliance factor in, or should this circuit have been run with 10/2 regardless of the amperage draw of the circuit?

Or does this have anything to do with the amperage draw? THe chart mentioned voltage drop. Does this mean the end of the circuit may be receiving <120v ?. Is this a dangerous situation? What kind of problems could I expect if any?

Thanks.