When I feel that the interior of the box might get water in it due to unusual circumstances (such as outdoor fixtures), I arrange the wire nuts so that they can "drain" out. Nothing like putting them "up" so that they are like little cups to hold water. I put them "down" at all outdoor and agricultural locations so that it won't matter if a bit of water gets in them. It should run out.
If your meat packing plant has boxes that water can get into during regular washdown, I might question whether they're using the proper boxes and fittings for that type of duty and location.
If your meat packing plant has boxes that water can get into during regular washdown, I might question whether they're using the proper boxes and fittings for that type of duty and location.