NEMA Enclosure Testing to NEMA 250 and UL 50E
Ensure your electrical enclosures provide the exact level of protection required for their environment. Our accredited lab provides comprehensive testing to the NEMA 250 standard, validating your enclosure's resistance to dust, water, and corrosion, and protecting your critical systems from failure.
- Protect Your Critical Systems: Validate your enclosure's design to prevent failures from dust and water ingress.
- Ensure Reliability in Harsh Environments: Prove your product's durability for indoor, outdoor, and corrosive industrial applications.
- Apply the Right NEMA Rating: Get the defensible test data behind the NEMA Type you mark on your product.
- Test with an ISO Accredited Partner: Test on calibrated equipment for precise, repeatable results that meet the highest industry standards.
Accredited environmental testing

ISO/IEC 17025
A2LA #5179.01

Controlled Goods Program
CGP registered
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The Challenge: The Enclosure is Your Product's First Line of Defense
Your electronic system is only as reliable as the enclosure that protects it. A failure to keep out dust, moisture, or corrosive elements can lead to short circuits, system malfunctions, and unplanned downtime. Choosing and validating the correct NEMA-rated enclosure is a compliance requirement and a long-term investment in the reliability and safety of your entire system.
Comprehensive Testing to NEMA 250 Standards
We provide testing to validate the full range of NEMA ratings, ensuring you select the most appropriate and cost-effective enclosure for your application.
- Indoor Protection (NEMA 1 & 12): We verify protection against light splashing and dust for enclosures used in controlled indoor environments.
- Outdoor Protection (NEMA 3, 3R, 4): Our testing simulates rain, sleet, snow, and wind-driven water to validate enclosures for outdoor use, ensuring they remain watertight and functional.
- Corrosion Resistance (NEMA 4X): For equipment in marine or industrial environments, we perform a rigorous salt spray test to validate the “X” designation, proving your enclosure’s resistance to corrosion.
- Specialized Testing: Our capabilities extend to testing for oil and coolant seepage (NEMA 13) and other specific industrial requirements.
Which NEMA Type do you need?
The Type number tells you where an enclosure may be installed and what it has been proven to keep out. Suffix X (3X, 3RX, 3SX, 4X, 6P) adds corrosion protection. PW may be added for high pressure power wash, and only to Types 3, 3X, 3S, 3SX, 4, 4X, 6, 6P, 12 and 13. Ratings are from ANSI/NEMA 250-2020, which applies to enclosures for electrical equipment rated 1000 V and below.
| NEMA Type | Where it is used | Meets at least IP (solids) | Meets at least IP (water) |
|---|---|---|---|
| Type 1 | Indoor | 2 or 3 † | 0 |
| Type 2 | Indoor | 2 or 3 † | 1 or 2 |
| Type 3, 3X | Indoor or outdoor | 6 | 5 |
| Type 3R, 3RX | Indoor or outdoor | 2 or 3 † | 4 |
| Type 3S, 3SX | Indoor or outdoor | 6 | 5 |
| Type 4, 4X | Indoor or outdoor | 6 | 6 |
| Type 5 | Indoor | 6 | 3 |
| Type 6 | Indoor or outdoor | 6 | 7 |
| Type 6P | Indoor or outdoor | 6 | 8 |
| Type 12, 12K | Indoor | 6 | 4 |
| Type 13 | Indoor | 6 | None |
| Type 7, 9 | Hazardous (classified) | Not applicable | Not applicable |
† Types 1, 2, 3R and 3RX meet IP2 or IP3 for solids depending on whether the enclosure is vented and where the live parts sit. Types 7 and 9 are hazardous location enclosures and are referenced out to UL 1203, so NEMA 250 defines no test for them here.
Three traps when converting NEMA to IP
- The conversion runs one way only. A NEMA Type tells you the IP degrees it meets or exceeds. An IP rating does not tell you a NEMA Type, and the standard says so outright.
- Dual marking voids the table. Where an enclosure is marked with both an IP rating and a NEMA Type, the conversion does not apply at all.
- “None” means insufficient, not equivalent. On Type 13 the IEC 60529 water evaluation is deemed inadequate to represent the NEMA test, so there is no IP number that stands in for it.
Frequently Asked Questions (FAQ)
The National Electrical Manufacturers Association (NEMA) provides standards for the design and construction of electrical enclosures. NEMA designations are a way of classifying the degree of protection provided by an enclosure against environmental hazards such as dust, water, and impact. The NEMA designation chart is a valuable tool for engineers, contractors, and facility managers to determine the appropriate enclosure rating for their electrical equipment.
NEMA 1 enclosures are intended for indoor use only and provide a basic level of protection against contact with live parts. NEMA 3R rated enclosures are intended for outdoor use and provide protection against rain, sleet, and snow. NEMA 3 rated enclosures offer the same protection as NEMA 3R, but are also suitable for indoor use. NEMA 4 rated enclosures provide protection against water, wind-driven rain, sleet, snow, wind, and falling ice. NEMA 4X enclosures provide the same protection as NEMA 4, but with added corrosion resistance.
The UL 50E standard defines the requirements for electrical enclosures that are intended for use in ordinary (non-hazardous) locations. UL 50E covers the safety, performance, and environmental requirements of enclosures and the electrical equipment housed within them.
NEMA testing involves evaluating the performance of an enclosure under specific environmental conditions and verifying that it meets the specified NEMA rating. NEMA X testing is a more rigorous test procedure that includes a salt spray test to evaluate the corrosion resistance of the enclosure.
Your Partner for Enclosure Reliability
Validate Real-World Protection
Our testing simulates rain, dust, and corrosion to confirm your enclosure protects the electronics inside it.
Expert Guidance on Ratings
Our team provides hands-on support to help you select and validate the most cost-effective NEMA rating for your needs.
Test with an Accredited Partner
Get accurate and defensible test data from our globally recognized ISO 17025 Accredited Lab.









