314.28(C) says boxes need covers compatible with the box and suitable for the conditions of use, and 300.5(E) says direct-buried conductors or cables shall be permitted to be spliced or tapped without the use of splice boxes. The splices or taps shall be made in accordance with 110.14(B), "Wire connectors or splicing means installed on conductors for direct burial shall be listed for such use."
So I go to troubleshoot a job last week and see sprinkler boxes enclosing weatherproof metal boxes, which should be ok to meet 314.29 for accessible boxes, but opening the j-boxes I see many boxes have an inch of water in them as the gaskets are not meant to be watertight, and some are open with mud in them. They used the blue wire-nuts with silicone sealant, but not done well, and some of the grounded conductors were nicked.
Sorry... so now for the question... am I missing a code section for boxes set on the ground in a sprinkler enclosure that would require sealed conduits entering these boxes, or that would not allow using the aluminum boxes we use for outdoor surface mounted work? The stainless steel covers and full 4-inch square black gaskets aren't going to keep moisture out. And 300.5(G) says conduits through which moisture may contact energized live parts shall be sealed or plugged at either or both ends... but if they used the sealed wire-nuts maybe that doesn't apply.
Sorry again... but 314.15(A) says in damp or wet locations boxes shall be placed or equipped so as to prevent moisture from entering or accumulating within the box and have to be be listed for use in wet locations. So if I put this kind of weatherproof but non-watertight box inside a sprinkler box on the ground, there is no way it will not collect water here in Oregon, so is that the answer? You can only use watertight boxes in the ground, or you may as well direct bury the wires and use the watertight splices? And those blue gel filled wire-nuts aren't meant to be used in underwater conditions are they?
Thanks... sorry it was so long.