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exposed underground conduit

exposed underground conduit

exposed underground conduit

(OP)
I recently visited a site where a new building was put up about a year ago. However when the new building was under construction and they broke ground, they damaged the feeder to an adjacent building. All the power was lost. So to patch it up they made a small man hole and spliced existing and added new  wiring to bring back power. But they did not replace the conduit, and left the cables exposed in the man hole. Recently there has been water build up in the man hole and water has run down the conduit and fried one of the main distribution panels in the adjacent buildings.  The man hole is about 24"X14" and 24" deep. The conduit entering the man hole is only about 2" directly above and on the same side as the conduit that is going down stream and feeding the adjacent building. Now I am wondering if I have any other options besides breaking ground and coupling a section of conduit in there to keep the water out or adding a drain in the man hole?

RE: exposed underground conduit

OZ Gedney makes a "conduit sealing bushing" which essentially is a rubber conduit plug with cores cut out of it that the conductors pass through.  There's even a split one made for retrofit so that you don't need to pull the conductors out to install it.  You put the rubber plug in, then there's a plate on each side and a bolt that runs through the whole thing, you clamp down on the plates with the bolt and the rubber squishes out of the "sandwich" to seal around the cables.  Works pretty well.  You might want to put one of these at each end of the conduit (at the handhole and at the switchboard).

Plumber's putty might also do the trick -- but it's not clear to me if there's any issue with solvents in the putty breaking down the cable insulation. . . .  One place that I know for sure that putty is often used in conduits is to prevent air flow through conduits -- but I don't know exactly what kind of putty is typically used. . . .

RE: exposed underground conduit

axd38

Peebee is right but the job is already done, it looks that the manhole is at a higher level than the panel.
I pressume that you cannot deenergize the panel for a long time.
Your best bet in this case besides of installing a new conduit section (difficult & expensive but best solution), is to seal the conduit stubs at the manhole and open the bottom of the manhole to let the water collected in the manhole drain to the soil.
The conduit might be full with water, depending of the type of cable it might not be suitable for constant inmmersion in the water, try to blow most of this water out with compressed air before sealing the conduit, this might prevent future headaches; be careful, this can be tricky as the panel will be energized, you want to push the water from the panel to manhole (uphill) and not viceversa as you do not want to splatter the panel guts with water and debris, temporarily seal your end with rags to force the air thru the length of conduit.
For sealing you can use DUXSEAL  or HILTI foam sealant these products are specifically for sealing conduits. Check the splices, they might need special insulation too as they will be submerged in the water. Hope this helps.

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