A #6 copper conductor will limit the voltage drop to 2% or less when supplying 50 amps for 80 feet on a 240 volt system.
14 gauge copper
10 gauge will work fine.
10 AWG.
12 gauge wire is sufficient. Any larger is fine, but superfluous.
4800
10 kw or 10,000 watts divided by 240 volts equals 41.6666 amps. 8 gauge is borderline so you will need 6 gauge wire to be safe.
The link below shows a typical usage and a chart
no
Yes 220 & 240 are considered the same.
Yes <<>> In North America, a three wire 120/240 volt system uses a neutral wire. For 240 volts two "hot" wires are used with no neutral.
A #10 wire with an insulation factor of 60,75 and 90 degrees C is rated at 30 amps.
A #6 copper wire with an insulation rating of 90 degree C is rated at 65 amps.