Understanding Enclosure Ratings, Ingress Protection and NEMA Ratings

Electronic products and mechanical devices that are exposed to any environment (indoor or outdoor) are commonly also exposed to people, dirt, and moisture. The purpose of the case, cabinet, or covering on any electrical/mechanical product is for protection as well as for beutification (cosmetics) and of course to bear a company logo. The design of the case, including vent holes and the placement of screws and fastening devices, determines how much protection the internal workings of the product has from the environment. These intrusions range from dirt, dust and insects to sprayed/dripped/directed moisture and curious poking fingers.

Ingress Protection is the industry standard term created by the International Electrotechnical Commission (IEC), and it is abbreviated IP (not to be confused with Internet Protocol (IP) - a completely different specification altogether). The NEMA (National Electrical Manufacturers Association) rating is a second and just as important rating. In the USA you will usually see a NEMA rating code. The IP code is more common on devices used internationally.

When looking at a security camera you may see a NEMA rating or an IP rating, or both - which can be confusing. Merely by seeing such a rating number you can be assured that at some point in the design process the product was submitted for testing by a third party authority that assigned the number. If you don't see an IP or NEMA number on something, then take care with placement since it is likely safe for indoor use only, in a protected area (no splashing water, not thrown dirt, dust and no splashing water or high humidity).

Without complicating things greatly, let's just say the camera chip set and the video sensor (CCD or CMOS) determine exactly how the AES operates when you turn the camera on, based upon available light. The object is to maximize exposure to gain a good image. Like mechanical shutters Automatic Electronic Shutters have a speed rating that determines exposure time, usually from 1/10,000th to 1/60th of a second. Since it is automatic you generally have no control, unlike a standard film based camera where you have mechanical adjustments (on good cameras, anyway).

NEMA Ratings Definitions

The table below shows a variety of NEMA rating numbers commonly used for products that are intended for placement in non-hazardous locations.