AWG # 10 wire.
12
For a typical use it would be 1/0 (one ought) wire in copper.
Use what is called bell wire or thermostat wire.
You would need to use a wire size that is rated for at least 40 amps to be safe and to meet the requirements of the air conditioner. A common wire size for this application would be 8 AWG copper wire, which is rated for 40 amps.
For a 70kW 240V single phase generator, you would typically use a wire size of 3/0 AWG copper wire. This size wire is rated to handle the current carrying capacity required for a generator of that size to ensure safe and efficient operation. Be sure to consult with a professional electrician to confirm the correct wire size for your specific installation.
To strip insulation off stranded wire, use a wire stripper tool and adjust it to the appropriate gauge size of the wire. Place the wire into the stripper tool and squeeze the handles gently, then pull the insulation off the wire. Be careful not to cut the wire strands while stripping the insulation.
Wire sizing is based on the amperage of the connected load. The wire size number 12 is rated at 20 amps.
# 6 wire
You need to look at the regulations that apply in your country. If in doubt, use a neutral wire of the same size as the live wire or wires.
10-32 unf-2a <<>> The wire size does not need to be calculated. Use a wire terminal end that crimps to the wire. These terminal end come in various wire sizes and bolt hole sizes. Pick the correct end for the wire size you are using and then in that wire size range, pick the correct bolt hole size that fits the bolt.
For 28 amps, you would typically use a wire size of at least 10 AWG (American Wire Gauge) for copper wire. This would ensure that the wire can safely carry the current without overheating. It's always a good idea to consult a professional electrician or refer to local electrical codes to determine the appropriate wire size for your specific application.