NEMA Rating
Noun
Definition of NEMA Rating
A NEMA rating is a standardized classification system that defines how well an electrical enclosure or housing protects internal components from environmental factors such as dust, water, corrosion, and other external conditions.
NEMA stands for National Electrical Manufacturers Association, the organization responsible for developing technical standards for electrical equipment across North America.
While NEMA ratings are commonly compared to IP ratings, there are key differences. NEMA focuses specifically on electrical enclosures, while IP ratings apply more broadly to all types of devices, including lighting fixtures and even smartphones.
NEMA Ratings Overview
Here’s a quick look at how NEMA types are grouped and what they’re designed for:
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NEMA Types 1, 2, 5, 12, and 12K: Indoor enclosures that protect against light dust and debris.
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NEMA Types 3X, 3RX, and 3SX: Outdoor enclosures with added corrosion resistance.
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NEMA Type 4X: Protects against water splashes, hose-directed water, windblown dust, and corrosion.
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NEMA Type 6: Can be submerged in up to 6 feet of water for 30 minutes.
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NEMA Type 6P: Can be submerged in up to 6 feet of water for 24 hours.
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NEMA Types 7–10: Designed for hazardous or explosion-prone locations.
For boaters, NEMA Type 4X, 6, and 6P offer the best protection for marine environments, roughly equivalent to IP66, IP67, and IP68 respectively.
Marine Applications of NEMA Ratings
If you’re outfitting your vessel with electrical components, you’ll want to focus on NEMA-rated gear that can handle exposure to spray, rain, and submersion.
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NEMA 4X – Ideal for deck lights, spreader lights, and fixtures exposed to salt and washdowns.
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NEMA 6 – Suitable for lighting and electronics that may experience brief submersion.
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NEMA 6P – Best for underwater or below-waterline installations.
For example, the Hella Marine 360° Compact Anchor Lamp LED is IP67-rated, equivalent to NEMA Type 6, meaning it can withstand temporary submersion without water ingress.
Example in a Sentence
“The NEMA rating of a lighting fixture provides valuable information on its ability to withstand specific environmental conditions.”