10 amps
It will taken 8 amps <<>> The conversion of 2.5 sq mm wire to AWG is equal to a #12 wire. The ampacity of a #12 copper wire with an insulation factor of 90 degrees C is 20 amps.
For 3-core twin and earth cables up to 4 sq mm with reasonable air circulation, allow 8 amps per sq mm for copper and 5 amps per sq mm for aluminium. For permanent installations with high usage per day, use 4 amps per sq mm.
4amps can pass in 1sqmm of wire max it is universal. In the UK 1 sq. mm wire can take 10 amps max according to tables. Cables that become warm in use should be replaced by a thicker gauge.
You will need a 40 amp breaker using AWG # 8 wire running it a distance of no more than 50 feet.
10 amps
It will taken 8 amps <<>> The conversion of 2.5 sq mm wire to AWG is equal to a #12 wire. The ampacity of a #12 copper wire with an insulation factor of 90 degrees C is 20 amps.
A 4 mm diameter copper wire with an insulation factor of 75 or 90 degrees C is rated at 65 amps.
It's ok up to 30 amps.
Wire gauge is determined by the capacity in amps. At 120 volts it requires 8.33 amps to provide 1000 watts. The typical residential application would require 18 AWG wire 1.024 mm in diameter.
The wire can be as big as you want to carry 6 amps. As a comparison, the smallest home wiring power circuit uses a #14 size wire and it is rated for 15 amps. In the UK a wire of 0.75 sq. mm is rated at 6 amps for portable appliances with occasional use. For a permanent installation a cable of 1 sq. mm. or more should be used. House wiring uses 2.5 sq. mm cable in a ring circuit to supply power sockets.
1 mm2 aluminium wire is not easy to buy but 1 mm2 copper wire is rated at 10 amps. Since the conductivity of aluminium is 7/12 that of copper, 1 mm2 aluminium wire would be rated at 7½ amps max (the same amount of heat is produced per metre by a current of sqrt(7/12) times that for copper).
5 mm
A 35 sq mm copper wire with an insulation factor of 75 or 90 degrees C is rated at 115 and 120 amps respectively.
For 3-core twin and earth cables up to 4 sq mm with reasonable air circulation, allow 8 amps per sq mm for copper and 5 amps per sq mm for aluminium. For permanent installations with high usage per day, use 4 amps per sq mm.
4amps can pass in 1sqmm of wire max it is universal. In the UK 1 sq. mm wire can take 10 amps max according to tables. Cables that become warm in use should be replaced by a thicker gauge.
Thicker wire does the job better but it costs more. The optimum wire for a continuous load would work at about 2 amps per square millimetre of wire cross-section. For the normal intermittent domestic load, small wire can be used up to 8-10 amps per sq. mm but it should not be allowed to become warm, if it gets warm a thicker wire is necessary.