Originally Posted by alien
It's usual to run individual wires through conduit just because they are easier to pull. There are also code requirements about overheating when putting bundled wires through conduit.
It's more than usual, it's by code. You buy the number of feet needed of each color then pull the wires through the conduit together. Sheathed wire is not designed for conduit.
Also, for larger amperages with 2 poles & a neutral, it's typical & usual to run the neutral a size smaller.
Also, if it's metal conduit all the way the conduit itself is the safety ground & you don't need the 4th wire. But this is assuming the conduit is installed correctly with all of the screws, etc properly tightened. This is true for metal pipe and EMT and flexible metal conduit.