How could I extend wiring from the subpanel to the water well 400ft away? The subpanel is connecting to the main panel using the #2 wire and 100ft from the main panel. I am thinking about 2 options:
1) With subpanel: Using load panel or what subpanel to use for each 200ft section? Running 2x200ft which wire size #6, #4, or #2?
2) Without subpanel: Running 400ft which wire size #4 or #2 directly from the subpanel to the water well?

What is the best way and why to supply power to the water well 400ft away?

You keep referring to things as "the well" and "the panel" like we know what you are talking about already.

You need to begin by giving us some detail about this project.
How big is the well pump?

I also have no idea what you are asking in #1).

400 ft is the same whether you run a single 400 or 2 X 200. What purpose is a subpanel? Before you can choose the wire you need the load rating for the pump. BTW 400 ft is a long way from the house for a well, considering the cost of piping and labor install, friction loss etc.

I like to run power from the house to the water well about 500ft away from the main panel with the current subpanel already in place.
I already run 100ft from the main panel rating 200A to the subpanel using #2 wire for the shed. Now, I need to run another 400ft to the water well. I could use another subpanel in between the 400ft or just another junction box to make the run easier due to the length. What size of the wire should I use?

The load should be around 220Vx30A = 6600W for the well pump.


Hopefully, that is clear up a little bit. Thank you all for your quick response.

I like to run power from the house to the water well about 500ft away from the main panel with the current subpanel already in place.
I already run 100ft from the main panel rating 200A to the subpanel using #2 wire for the shed. Now, I need to run another 400ft to the water well. I could use another subpanel in between the 400ft or just another junction box to make the run easier due to the length. What size of the wire should I use?

The load should be around 220Vx30A = 6600W for the well pump.


Hopefully, that is clear up a little bit. Thank you all for your quick response.
@
Southwire voltage drop calculator indicates #2 copper. I used 240VAC and 30 amps

Thank you ma0641.

It will be costly about $3,000 but to get a new service at the pump in will cost about $7,000. I am thinking about a remote solar pump system too but I don't know much about it and may cost more than $5,000. I think this the best way.

No joke here. Wouldn't it be easier, cheaper and more logical to put in a new well closer to the house?

Don't think a solar outfit would supply enough power. Even with that you would need a lot of batteries and if you use the well a lot, on a cloudy day, may deplete the batteries. Really, I had a 300 ft. drilled well installed with pump, piping to house(100 ft) and tank for less than $5000