Referring to a typical water sump with pumps and floats, there is always
a danger of gasses in below ground installations. When bringing the cabtire
cables out of the sump and into a connection box above ground I have seen
some engineers specify that the cables must be sealed with a hazardous
area type seal with the poured compound.
This is horribly impractical because the failure of one pump or float would
require replacing all the equipment in the sump because all the cables
would need to be cut.
In order to prevent underground or sewer gasses from entering the junction box
and traveling into the control equipment I have often run the cables out of the
side of the sump and direct buried them. They then enter the junction box using
the normal waterproof connectors. this is not practical either because the cable can be damaged with a shovel. Another way is a short stub of PVC conduit large enough for all the cables, usually 6, to get you below ground near the sump
and then the cables are direct buried from there. The top of the conduit in the junction box can be sealed with silicone or duct seal to keep the gasses out
of the electrical system.
None of this sounds legal to me and I wonder if there is a code and end user friendly way to install sump pump wiring so that I do not have to worry about a rejection.
