In this series of blogs we are looking at the various NEMA ratings, and what they mean for selecting the enclosure for a control panel.
We know that NEMA has ratings of 1 through 13 for panel enclosures, and also that normally it’s NEMA ratings 1, 4 and 12 that usually apply when selecting a control panel.
NEMA 3
Control panel enclosures that are rated NEMA 3 are constructed for use either indoors or outdoors, provide a degree of protection to personnel against incidental contact with the enclosed equipment; provide a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and ensure that those control panel enclosures will be undamaged by the external formation of ice on that enclosure.
NEMA 3R
A control panel built to NEMA 3R standards provides all of the protection of the class 3 rating, except that it does not provide protection for the contents against wind blown dust.
NEMA 3S
Controls panels with this rating have all the protection that is included in NEMA 3, as well as ensuring that any control panel external mechanisms will remain operable when the control panel is ice laden.