Submerged Cables

[W@ttson]

Hello,

Have a project where the contractor has been careless and has left in-ground pull boxes open in an industrial environment during construction. The pull boxes are part of the new work and all of the conductors inside are supposed to be new. The boxes are large cast iron boxes that are supposed to be NEMA 4X rated (think of large junction boxes for street lighting applications). During the last 2 years the boxes have been open and have been getting filled with water and the water has been lingering for the majority of that time. The water is contaminated with oils, dirt, debris, salt (marine environment). The cable insulation is XHHW2.

If they pump out the water from these junction boxes would these cables still be fit for continued service?
I assume someone will ask what the insulation resistance reading is on the conductors (I don't have that information) - say they let the cables dry and the test comes back above NETA minimums, is there any more that can be done?

Are there any guidelines out there with how to handle flooded electrical installations?

 

[ModbusMan]

Cast iron plus salt water? And I hate just getting my camping skillet wet...

 

[ptonsparky]

Depends. The insulation itself may not have an issue but if the conductors and splices have been contaminated, all bets are off on those.

 

[Julius Right]

If the boxes are employed only as pull-boxes that means no water ingress is expected to be done if the insulation and jacket is not damaged.
This is the cable in a manhole of a duct bank case which is full of water 6 months in a year, usually.

 

[jim dungar]

Cast iron plus salt water? And I hate just getting my camping skillet wet...

For sure.
But, the OP sounds like they may be of the heavy duty cast iron used in sewer grates and manhole covers.

 

[Elect117]

boxes are indoor or outdoor?

If outdoors, they should have rock under the boxes and small holes so they drain naturally. If indoors and this is a spray room, then moisture will always end up in there. They make splices that can be submerged and that might work out for your use case. Like a polaris tap but more coverage.

Wires being submerged is not typically a problem if you have the right wire type. The oils and unknown solvents might be. I would clean, trim back, and remake the splices, and strap them to the sides so that they don't sit at the bottom of the box (if capable). I would advise the building owner to have their maintenance guy check for water fill occasionally and call to you or another electrician to pump it.

 

[W@ttson]

there are no splices inside. Its like a large handhole that is hot dip galvanized cast iron. I can understand if this was an existing condition but it for a new installation to accept such an install is tough to get over. If the pullboxes had their gaskets covers installed, then the water intrusion would not have happened.

Would you be inclined to accept it on behalf of your client?

 

[Elect117]

Pump the water out, do an insulation test, and sleep well at night.

I would just be happy nobody tripped over it or fell in.