NEMA and IP Rating
Intro to NEMA and IP Ratings:
NEMA – National Electrical Manufacturers Association
IP - Ingress Protection
These are the rating systems/standards used to describe the degree to which the product (Especially electrical enclosures and medical devices) should be protected from liquids like water/oil, dust and other corrosive chemicals, among many other things. Whether you’re an engineer, inspector or installer, choosing an electrical enclosure with the right levels of protection is paramount to worker safety.
- NEMA Rating System: NEMA standard 250 is primarily used in USA and Canada
- IP Rating system: IEC standard 60529 is mostly used in Europe and across the world
- Because the two systems use different test parameters, they are not directly comparable or easily converted.
- NOTE: An IP rating considers only protection against ingress of solid foreign objects and ingress of water, while NEMA ratings consider these and other specifics such as corrosion and construction details.
What exactly is NEMA rating?
- NEMA standards describe each type of enclosure in general and functional terms, and specifically omits reference to construction details. In other words,
- NEMA specifies what an enclosure must do, not how to manufacture it. NEMA ratings use different numbers to represent protection levels for electrical enclosures.
- It is not mandatory for all electrical components to be designed or built with a NEMA enclosure. Instead, NEMA ratings are merely used as an industry standard and are completely voluntary.
- Infographics on NEMA to help you understand better: https://cdn2.hubspot.net/hubfs/1646803/CBC/Documents/CBC-NEMA-Ratings-Final.pdf?t=1536594581867
NEMA 1 – NEMA 1 enclosures are constructed for indoor use and provide protection against human contact with electrically-charged, live electrical parts. It also protects the equipment from falling debris (dirt).
NEMA 2 – A NEMA 2 enclosure is, for all intents and purposes, the same as a NEMA 1 enclosure. However, a NEMA 2 rating additional protection than the NEMA 1, including protection from light dripping or splashing of water (drip-proof). NEMA 3R, 3RX – NEMA 3R and 3RX enclosures are engineered for indoor or outdoor use and protect against rain, sleet, snow, dirt, and prevents the formation of ice on its enclosure.
NEMA 3, 3X – NEMA 3 and 3X enclosures are rain-tight, sleet-tight, and dust-tight and are made for both indoor and outdoor us. NEMA 3 and 3X designates added protection against dust beyond a NEMA 3R or 3RX enclosure.
NEMA 3S, 3SX – NEMA 3S and NEMA 3SX enclosures benefit from the same protection as a NEMA 3, however provides protection when ice forms on the enclosure and will remain operable when covered in ice.
NEMA 4, 4X – NEMA 4 and NEMA 4X enclosures are intended for indoor or outdoor use and provide the same protections as a NEMA 3 enclosure with additional protection against water ingress and/or hose-directed water. So, if you need to clean off your NEMA 4 enclosure, you don’t have to worry about water damaging your electrical components.
NEMA 6, 6P – Offering the same protection as a NEMA 4 enclosure, NEMA 6 offers protection from temporary or prolonged (6P NEMA rating) water submersion up to a designated depth.
NEMA 7 – Also built for hazardous locations, a NEMA 7 enclosure is explosion proof and made for indoor use (built for hazardous locations).
NEMA 8 – Offering the same protection as a NEMA 7 enclosure, the NEMA 8 can be used both indoor and outdoor (built for hazardous locations).
NEMA 9 – NEMA 9 enclosures are dust ignition proof and intended for indoor use in hazardous locations.
NEMA 10 – NEMA 10 enclosures meet MSHA (Mine Safety and Health Administration) standards.
NEMA 12, 12K – NEMA 12 and NEMA 12K enclosures are intended for general purpose, indoor use. The NEMA 12 and 12K enclosures protect against dripping and splashing water, are rust resistant, and do not include knockouts (partially punched openings that can be removed to accommodate cables, connectors, and/or conduits).
NEMA 13 – NEMA 13 enclosures are for general purpose, indoor use. They provide the same protection as
the NEMA 12 enclosures, but with added protection against dripping and/or sprayed oils and coolants.
*Note – An enclosure designated with an “X” indicates a corrosion-resistant rating.
NEMA Comparison Chart
Fig: NEMA Chart for Non-Hazardous applications