NEMA vs IP rating — how the two enclosure systems compare

| NEMA type | Indoor / Outdoor | IP approximate equivalent | Typical use | |—|—|—|—| | NEMA 1 | Indoor | ≈ IP20 | Indoor general purpose, no waterproofing | | NEMA 2 | Indoor | ≈ IP22 | Indoor with limited dripping water | | NEMA 3 | Outdoor | ≈ IP54 | Outdoor rain, snow, windblown dust | | NEMA 3R | Outdoor | ≈ IP24 | Outdoor falling rain and ice (no dust ingress rating) | | NEMA 3S | Outdoor | ≈ IP54 | NEMA 3 + external ice-loaded mechanism operation | | NEMA 4 | Indoor / Outdoor | ≈ IP65 or IP66 | Direct water spray, dust-tight | | NEMA 4X | Indoor / Outdoor | ≈ IP66 + corrosion | NEMA 4 with corrosion resistance (typically stainless) | | NEMA 6 | Indoor / Outdoor | ≈ IP67 | Occasional submersion at limited depth | | NEMA 6P | Indoor / Outdoor | ≈ IP68 | Prolonged submersion at limited depth | | NEMA 12 / 13 | Indoor | ≈ IP54 or IP65 | Indoor industrial, dust-tight, oil-resistant |

The mappings are approximate. A NEMA 4 enclosure is roughly equivalent to IP65 or IP66 depending on its specific water-spray test result. A device rated NEMA 4X is not automatically equivalent to IP66 + stainless construction — the manufacturer may have tested for one and not the other. Always check what specific ratings the manufacturer has published, not what the cross-reference table suggests. For the full IP rating structure underpinning these equivalents, see our overview of ingress protection ratings.

NEMA covers four environmental factors that IP does not test:

For deployments where any of these factors matter — marine (UK MCA / Lloyd’s Register, US USCG / ABS), food and beverage (UK BRC / FSA, US FDA / USDA), outdoor cold climates, machine tool environments, chemical processing — the NEMA designation can be more meaningful than the equivalent IP rating, even when the project’s specification language uses IP.

IP covers two factors that NEMA does not test with the same precision:

For deployments where a specific cleaning regime drives the specification — food sanitary wash-down, semiconductor cleanroom dust control, pharmaceutical particle counts — the IP rating’s test precision is the relevant specification line.

A few of the most common cross-system specification questions:

Is NEMA 4X the same as IP66?

Not exactly. NEMA 4X protects against direct water spray (similar to IP66’s water-jet test) AND adds corrosion resistance (typically through stainless steel construction). IP66 protects against direct water spray but does not test for corrosion. For a coastal or food-processing deployment, the right specification is often “NEMA 4X stainless steel construction with IP66 rating” — both designations, not one or the other.

Is NEMA 4 enough for outdoor use?

Usually yes, for North American climates. NEMA 4 is roughly equivalent to IP65 or IP66 and is designed for direct outdoor exposure. For cold climates with freezing rain or ice loading — northern US states, Canadian provinces, Scottish Highlands — NEMA 3R or 3S adds the ice-resistance validation NEMA 4 alone does not include. For coastal or marine outdoor deployments, NEMA 4X is the typical specification.

What is the NEMA equivalent of IP69K?

There is no direct equivalent. NEMA does not specify a high-pressure, high-temperature wash-down rating that matches IP69K’s DIN 40050-9 conditions. Food-industry equipment for North American markets typically carries both ratings — NEMA 4X for corrosion resistance and IP69K for wash-down compatibility — listed separately rather than equated. UK BRC and US FDA / USDA / 3-A Sanitary Standards both treat the combined specification as acceptable.

Can I substitute one rating for the other?

With caution. The cross-reference mapping is approximate. For most general-purpose specifications (indoor industrial, outdoor sheltered, light wash-down), either rating is sufficient as long as the equivalent is checked against the actual deployment environment. For specialised environments (marine, food sanitary, sub-sea, cleanroom, hazardous-area), both ratings often matter and the specification should call out both.

For equipment that will be deployed across both North American and international markets, or for deployments where multiple environmental factors matter, dual specification is the safer approach:

The combined specification is more demanding to source but typically not significantly more expensive — most industrial-grade equipment rated for one standard meets the other at the equivalent level.

Things Embedded’s product range spans the full IP65 to IP69K range with NEMA equivalents listed against each rating — across UK and US markets equally. For multinational deployments, food and beverage applications, marine equipment, and any environment where corrosion or chemical resistance is a parallel concern, our engineering team scopes both the IP and NEMA specifications against the deployment, rather than substituting one for the other.

If you would like help working out which combination of IP and NEMA ratings your project needs, send us:

…and we will shortlist practical options that satisfy both rating systems. Call +44 (0)1785 558 300 or email sales@things-embedded.com.