You wouldn’t put a quart of engine oil in a vehicle without understanding engine oil ratings, and you wouldn’t stake your coworker’s life on a safety strap without knowing the strap’s weight rating. In much the same way, electrical and electronics enclosure buyers should be familiar with the ins and outs of enclosure ratings before they select an electronics enclosure model.Here, we’ll do a head-to-head comparison of two popular enclosure ratings: NEMA 4 enclosures vs. IP65 enclosures. Each rating can tell an enclosure buyer a lot about what they can expect from a given model of enclosure so let’s get familiar.
business man making decision concept

The Basics of NEMA and IP Ratings

NEMA and IP ratings are two different systems for rating and categorizing the performance of electrical enclosures. Here’s a quick introduction to each one:
  • The National Electrical Manufacturers Association (NEMA) rating system is used primarily in the U.S. It uses one- or two-digit numbers, plus letters in some cases, to identify the degree of protection that an enclosure provides against hazards such as dust, dirt, rain, snow, ice, corrosion, oil, washdowns with hose-directed water and much more. The scale starts at its least protective rating, NEMA 1, and ascends to its most protective rating, NEMA 6P, although it doesn’t always move in strict numerical order. 
  • The Ingress Protection (IP) rating system is an international standard that’s used throughout the U.S., EU and the UK. It’s a two-digit number in which each digit rates the enclosure’s level of protection. The first digit rates the enclosure’s dust protection on a scale from 1 to 6, while the second rates its liquid protection on a scale from 1 to 8. The ratings themselves are established by the International Electrotechnical Commission (IEC) in its IEC 60529 standard.
NEMA ratings and IP ratings don’t have a strict one-to-one correspondence since the scales take different factors into account. However, it’s usually possible to find two that are roughly equivalent to one another.Polycase SB-34 nema enclosure

Polycase SB-34

NEMA 4 vs. IP65: What’s the Difference?

In general, an IP65 enclosure and a NEMA 4 enclosure will provide roughly comparable levels of protection. Many Polycase enclosure boxes feature both of these ratings due to their similarity in standards.The differences between a NEMA 4 rating and an IP65 rating come down to the criteria that are used to rate them. An IP65-rated enclosure is rated on two criteria only: dust ingress protection and liquid ingress protection. By contrast, a NEMA-rated enclosure can have other rating criteria, such as corrosion resistance or ice formation.For example, in the case of NEMA 4X enclosures vs. IP65 enclosures, the main difference between the two is corrosion protection. Since IP enclosures are not rated for protective qualities against corrosion hazards, a NEMA 4X enclosure is a must-have for applications that demand corrosion resistance. Such applications might include a junction box to protect the electrical connections of marine equipment or an electrical box which will be exposed to harsh chemicals in an industrial facility.

NEMA 4- and IP65-Rated Enclosures from Polycase

Polycase makes it easy for our customers to find the NEMA enclosures and IP enclosures that will protect their most critical electronic and electrical equipment. We’ve got numerous options that feature NEMA 4, IP65 or even higher ratings. Our NEMA and IP ratings are certified through rigorous testing by Underwriters Laboratories. Check out a few of our best NEMA 4 enclosure and IP65 enclosure options:
  • The Polycase WP Series features both IP65 and NEMA 4X ratings. Constructed from rugged polycarbonate and featuring a silicone rubber gasket, the WP Series offers an ideal balance of outdoor-rated performance and cost-effective design.
  • Carbon steel enclosures are known as durable solutions for industrial enclosure applications, and the Polycase SB Series offers a perfect example. These hinged steel enclosures come with NEMA 4X and IP66 ratings and offer a high-performance weatherproof design constructed from 16-gauge steel, with a rubber gasket for watertight protection.
  • Polycase’s stainless steel SA Series enclosures also feature a NEMA 4X/IP65 rating. Thanks to the natural corrosion resistance of stainless steel, these models are among our most popular choices for applications where protection from corrosion is a high priority. They also feature hinged covers with a keyed latch for built-in security.
  • For the ultimate in cost-conscious performance, our WA Series of ABS plastic enclosures is a great choice. NEMA 4X- and IP65-rated, these enclosures offer many of the same features as our polycarbonate enclosures, but at a lower price point that’s perfect for mass-production devices.
Polycase WA-23 nema enclosure

Polycase WA-23

Make sure to also browse our full selection of electrical and electronics enclosures to evaluate the many enclosure types and designs we have available. Need a little help with the fine points of NEMA and IP ratings? Our experts can help you find exactly what you’re looking for. Just call us at 1-800-248-1233 or get in touch online.
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