the gauge of the wire determines how much amperage a wire can carry
the insulation determines how much voltage the wire can handle
The amps that a four gauge wire will handle will depend with the thickness of the wire. If the wire is thin, the four gauge will handle 95 amps.
1440
You would need to use a #12 copper conductor to continuously draw 14 amps at 120 volts.
5000 watts
30 amps.
14 gauge wire is for 15 amp circuits. At 220 volts that would be enough for 2.4 kw.At 120 volts it would need 12 gauge wire which is rated for 20 amps.
6 AWG will handle 50 amps with a voltage drop of about 4 volts. If you go to 4 AWG and limit to 50 amps your voltage drop will be 2.5 volts.
34.539 miliamps is only 0.034539 amps. A 16 gauge wire will handle that.
600 watts
5 amps
15 amps
10 guage