Submersible Pump Connection Clarification

[RRoc]

I have not worked with submersible pumps very much. I'm running conductor wire to connect to two new pumps to the left of the picture.
The picture attached shows an existing junction box where the submersible pump connects to the Soft Start via the junction box.

Details
100 HP Pump
480VAC
4/0 wiring being ran to junction box.

The Submersible Pump Mfg tells me the lead wires coming out of the pump casing are smaller because the lead wires are submersed in water and that once the lead wires exist the Pump casing that I need air tight or water tight connection.

My question is do I need to state that on the Conduit Drawing I am making or will the electrician knows this already?
Also not sure if the wires will be spliced or landed on terminal blocks in the junction box.

Any guidance will be greatly appreciated to ensure electrical connections are correct.

 

[tom baker]

Typically wires are spliced, For this I would use 2 hole compression lugs, ss hardware and T&B motor stub boots.
Question for you, why are there 3 flex conduits from the wellhead to the j box?
Is the Jbox large enough for 4/0?

 

[petersonra]

There is no way to know what the electrician that hooks it up knows. If there is anything special that needs to be done to hook it up, it is best to put a note on the drawing. My personal opinion is you should get whatever written material you can from the manufacturer on what they expect and make that an addendum to the drawing so the guy hooking it up doesn't have to go hunt it down.