...There is no requirement for NEMA 12 paint to be UV resistant....
The NEMA 12 enclosures that I use all have the same clamps as the NEMA 4. The difference is that the NEMA 12 only has clamps on the side opposite the hinge and the NEMA 4 has clamps on the other two sides in addition to the one opposite the hinge. Also on the larger enclosures there will be more clamps along a side on a NEMA 4 as compared to a NEMA 12. I assume that the extra clamps are needed to meet the "pressurized stream" test.It's no accident that very many NEMA-12 enclosures are also rated for NEMA-4. In practical terms, the only difference between the two tests is that for NEMA 12, the oil is not directed at the enclosure as a pressurised stream, and that many NEMA 4 gaskets are dissolved by contact with oil. These are fine points; with readily availably materials, it's pretty hard to make a NEMA-12 enclosure that's not also NEMA-4 rated, and vise-versa. Again, in practical terms, the difference (if there is one) will be that a NEMA-12 will have a door with a handle, while a NEMA-4 will have little clamps.
No.
A NEMA 12 enclosure is not tested for having liquid 'pool' against the gasket. There is no requirement for NEMA 12 paint to be UV resistant.
Most manufacturers do make a drip hood for their NEMA 12 enclosures, but they are still probably only listed for indoor use.
Most manufacturers do offer a NEMA 3/12 dual rated enclosure family, that many people generically still call NEMA 12.
regardless of what kind of dress you put on the pig. Its still an indoor pig. .
"still an indoor pig."
You miss the point.
If you're making an academic argument that a NEMA 12 rating has no relation to indoor / outdoor use, you're correct. For that matter, an "explosion proof" (Nema 9) rating has absolutely nothing to do with the indoor / outdoor rating. Heck, you really get down to it, even NEMA-3R and NEMA-4 ratings have nothing to do with 'indoor' or 'outdoor' applicatiuons.
You have to look at the testing criteria, and choose the location that apply. NEMA-3R is tested against an artificial rain at a certain angle; we equate this to being outdoors in a wet location. NEMA-4 gets a stream of water applied at every angle possible. NEMA-12 gets oil dripped on it, and the oil isn't supposed to enter.
If you want to get technical aboput it, it's very possible for a location to require enclosures to be both NEMA 12 and NEMA 4.
But that's just armchair philosophy in so many instances. In practical terms, the same methods are used to meet each of the challenges. It's pretty hard to make an enclosure that meets only one, but not the other two as well. Chances are, those little drip shields are more a response to customer demand than a necessity for the enclosure to actually pass the test. Yet, when you look back at the test - "rain" at a slight angle - that little piece of sheet metal may be all that's needed to make a NEMA-1 enclosure pass the NEMA-3R test.
Look again at those NEMA-12 enclosures. Gaskets aside, you'll likely find a flange that forms a gutter around the door opening. Then go look at the door of your car. Do you see a similar gutter (though cars have the gutter on the door itself?) Do you think that gutter can tell the difference between water and oil?
I wouldn't worry too much over the fine print.
"still an indoor pig."
You have to look at the testing criteria, and choose the location that apply. NEMA-3R is tested against an artificial rain at a certain angle; we equate this to being outdoors in a wet location. NEMA-4 gets a stream of water applied at every angle possible. NEMA-12 gets oil dripped on it, and the oil isn't supposed to enter.
But that's just armchair philosophy in so many instances. In practical terms, the same methods are used to meet each of the challenges. It's pretty hard to make an enclosure that meets only one, but not the other two as well. Chances are, those little drip shields are more a response to customer demand than a necessity for the enclosure to actually pass the test. Yet, when you look back at the test - "rain" at a slight angle - that little piece of sheet metal may be all that's needed to make a NEMA-1 enclosure pass the NEMA-3R test.