When you want to choose electrical enclosures, there are 2 factors you should consider
First, which environment will you use it? Is it indoor or outdoor?
Second, what level of protection in above environment that is required?
NEMA has defined a structure to different NEMA definitions (NEMA definitions link to page) on protection to 13 levels, to establish us identify which type of enclosure will suitable to protect the enclosure and equipment inside. The result of selecting a wrong type of enclosure can lead to inferior protection for inside equipment in a particular environment.
The most common error choosing between NEMA 4 and NEMA 12 is a lot of customers assume they need NEMA4 protection rating for there application, however it might overwhelming what it should be resulting in unnecessary cost they have to pay. This is a conclusion of environment that suitable for NEMA 4 and NEMA 12
If it will be used under outdoor environment, expect windblown dust and rain, splashing water, and hose-directed water. We would recommend you to use a NEMA 4 enclosure.
If it will be used under an indoor environment, only expect windblown dust, hot temperature, a little bit of splashing water expected. We would recommend you to use a NEMA 12 enclosure.
However, if you are not sure which NEMA rating should you use please check it out NEMACOTM page NEMA ratings
NEMACOTM offer NEMA 4 and NEMA 12, in different materials, Aluminum, Carbon steel, Stainless steel with a choice of colors white, light gray (ASA70), dark gray (ASA 61) and black.