river pump (irrigation) electrical issues

[rvcoaster]

i'm having an issue here with an irrigation system fed by a river pump. river pump is some 300-400' from residence and is fed by what apears to be 2 gauge or bigger THWN or similar in conduit (220V, and either no ground or no neutral, not sure yet). unknown if conduit is actually home run to the household or if at some point becomes incorrectly buried cable (like a few other things around this residence).

working on this house i am finding that NOTHING has been done correctly so i am highly suspect of this install but has functioned for 25 years.

two winters ago the river flooded to epic proportions and damaged everyones sprinkler pump setup, in fact some folks cannot find their setup at all due to the river depositing around 3' or so of sludge on the banks. last summer the river stayed flooded until late fall so no irrigation happened at any of these residences. this year the river is fine, and repairs are required.

i went out and found the tip top of my electrical junction box buried in the mud. this box had previously been around 3' higher than the ground - like i said the river deposited 3' of mud on the bank. the junction box is so heavily damaged by the flood (metal box, dented, missing cover, partially ripped off of conduit) that i have to repair it and would assume replace it altogether.

junction box is screwed to a 4x4 post. i have dug a hole in this clay around 3 feet deep and around 6 feet wide to gain access to the box/conduit. the electrical outlet box is destroyed along with the metal conduit that connected the junction box to the outlet box.

i am trying to determine if the conduit in fact goes to the house or just ends in the ground (like the connection between the house and garage) as i would like to install a new post and have the entire electrical connection system up high around 6' above current ground (or 9' higher than the ground used to be).

at this point however it is looking like i need some type of splice where the current junction box is, and this is an area that gets submerged frequently. right now the splices inside the box look like ground rod clamps covered in silicone and tape. i dont think this was done right.

in any case the top of the junction box is level with where the ground currently is. i'm not sure what to do. what i have dug up and moved will fill in over time with flooding and so i would like the whole shebang to be raised up very high if possible.

i'm no electrical expert but i know enough to be able to dig a trench, run conduit and pull wires through it to install a subpanel in an outbuilding and have it pass but this underwater thing is way out of my league. at this point i dont really know what to do.

can anyone help me?

 

[pattenp]

Assuming the wiring is individual wires that are rated for wet locations, clean the wire jacket well and use splice/reducer connectors and wrap for a length of a couple inches pass the ends of the connectors with a couple layers of self sealing rubber waterproof tape and top off with a couple layers of good quality electrical tape.

 

[VHF]

Although there are splices rated for wet locations, I would be leary of any solution involving a splice that will even somtimes be under water.

Better would be to dig back a few feet along the cable and pull it up into a new above-ground (and hopfully above-water) junction box a few feet closer to the house, the run new wires to the pump as needed.

3-wire was the old norm for 240V feeds to detached structures/equipment. If the pump is 240V, it may not need a neutral, in which case your 3rd wire can be a true equipment grounding conductor (EGC). Otherwise, it may serve as both neutral and ground ("grounded conductor"), in which case I would consider the addition of a couple of ground rods at the pump location (such as would have been requried for a detached structure using a 3-wire feed.)

In any case, you'll want to trace these wires at the house end and find out exactly where they originate in your main panel (or subpanel) and exactly where the 3rd wire is connected.