When do you use a neutral in 220V single phase?

Question

Are there guidelines that determine when a neutral is required in 220V single phase power as opposed to the two hots and a ground? How do you know when you need a neutral? Is it purely determined by the device you are hooking up? If so, how do you know whether it needs a neutral? Example, if you bought a drill press that was 220V and has a plug on the end, how do you know whether to use a neutral without cutting the plug off?

Answer 1

Dryers and ranges generally are the only 220 circuits that need a neutral. Thats because certain functions of each require 120V, hence the need for a neutral.
There was a time when the equipment grounding conductor was used as a neutral, but this practice can (under the right circumstances) cause the equipment itself to become live (hot). Some folks woul d get a nasty shock from the frame of the equipment. Especially standing on bare concrete, and around grounded water pipes

Answer 2

220v is the equivalent of 2 120v circuits on a single device(hence why 2 hots), if the device requires a neutral then the plug will be 4 pole instead of 3 pole. you do not install a neutral every time. If the device requires a neutral it means that portions of the device use 120v .

Answer 3

You use the neutral all the time, every time. You also use the bare or green wire for an equipment ground.
The plug should be 4 prong now.

Answer 4

Just run your 220 line to your 220 recepticle and everything should be in place.