Assuming its copper. Number #3 or #2 is fine
AWG 4 copper.
That can't be answered until you state the voltage.
Service wire for 100 amps requires AWG #3 copper.
20Sqmm
I would recommend you use AWG # 2 copper or AWG # 1/0 aluminum for that distance and amperage.
AWG 4 copper.
That can't be answered until you state the voltage.
A 100 amp residential service requires a size #8 copper wire, it should be insulated in green.
This is a voltage drop question. A voltage must be stated to answer this question.
Service wire for 100 amps requires AWG #3 copper.
A 100 amp service requires that you use AWG 4 copper wire or AWG 2 aluminum wire.
2 copper
2AWG.
20Sqmm
AWG # 4 copper.
A 3/0 aluminum conductor will limit the voltage drop to 3% or less when supplying 150 amps for 150 feet on a 240 volt system. This size will allow the conductor to be loaded to 120 amps. 150 x 80% = 120 Conductors are only allowed to be loaded to 80% or their rated capacity. If you need the full 150 amps then you would need to use a wire with a rating of 190 amps. 190 x 80% = 152 amps A 4/0 aluminum conductor will limit the voltage drop to 3% or less when supplying 190 amps for 150 feet on a 240 volt system.
For Service Entrance Cable 600 kcmill (Thousands of circular mils).