I want to attach a 120V outlet to the side of an outdoor "main lug" enclosure.
The outdoor-rated "main lug" box has knockouts on the bottom and sides.
The outdoor-rated single gang junction box has threaded holes in the back and sides.
It seems obvious to knock out one of the knockouts, and use a threaded fitting to attach the jbox flush to the side of the main lug box.
But - how to make the connection waterproof? Is there a gasket or a special fitting for this purpose? Or would using silicone caulk be good enough?
Or is there no code-compliant way to do this, and instead, I must use flexible NM conduit and watertight fittings? This is less desirable, because it is less compact.