UL-approved components must meet technical standards, be designed in compliance with regulations, and be accepted by the certifying authority in the project. Especially for enclosures, the right certification is often the decisive factor and sometimes it is what wins or loses the order.
That is exactly why we are pleased to announce an important milestone:
Our MBI enclosure series is now officially UL-certified! 🎉
What does UL stand for? 🤔
UL stands for Underwriters Laboratories, today UL Solutions, one of the world's most recognized product safety testing organizations. UL was founded back in 1894 in the United States, and since then the UL mark has become a true seal of quality in North America. Anyone looking to market electrotechnical products there can hardly avoid UL.
Unlike the CE mark, which is a manufacturer's self-declaration in Europe, UL listing is based on an independent assessment by UL itself. The product is tested in a laboratory, the manufacturing is audited and only those who meet all requirements are allowed to carry the UL mark. It is a demanding process, but that is exactly what makes it so valuable.
What exactly has been certified at MBI? ✅
Our MBI series has been officially assessed by UL Solutions and certified to the requirements of UL 508A. The issued Certificate of Compliance confirms that our MBI series was tested in the product category NITW - Industrial Control Panels and meets all requirements.
🇺🇸 USA
Standard: UL 508A, Edition 3 - NITW - Industrial Control Panels
🇨🇦 Canada
Standard: CSA C22.2 No. 14, Edition 13 - NITW7 - Industrial Control Panels
The MBI series is listed for the following Environmental Type Ratings:
Type 1 - Indoor use Protection against contact and falling dirt
Type 4 - Indoor and outdoor use Protection against splashing water and water jets
Type 4X - Same as Type 4, with additional corrosion protection
This makes the enclosures suitable even for demanding industrial environments, whether for indoor installation, outdoor use, or corrosive atmospheres.
What does NEMA 4X stands for?
NEMA 4X is a U.S. enclosure rating classification (similar in purpose to the IP rating used in Europe), published by the National Electrical Manufacturers Association (NEMA). It is the North American counterpart to the European IP rating (per IEC/EN 60529).
An enclosure with this rating provides protection against:
Ingress of solid objects and dust
- Protection against falling dirt
- Protection against windblown dust
Ingress of water
- Protection against rain, sleet, and snow
- Protection against splashing water
- Protection against direct hose-down
Mechanical stress
- Protection against external ice formation on the enclosure
- Protection against damage caused by external icing
Corrosion
- Additional protection against corrosive environments
- Suitable for salt spray and chemically loaded atmospheres
Meaning of the "X"
NEMA 4 = watertight (hose-down rated), but not necessarily corrosion-resistant NEMA 4X = same as NEMA 4, plus corrosion resistance
Comparison to the IP rating
A rough (not exact) comparison:
| NEMA | Roughly comparable to IP |
|---|---|
| NEMA 1 | IP20 |
| NEMA 3R | IP24 |
| NEMA 4 | IP66 |
| NEMA 4X | IP66 + corrosion protection |
| NEMA 6 | IP67 |
| NEMA 12 | IP52 / IP54 |
| NEMA 13 | IP54 |
What do the individual areas on the UL label mean?
This is the actual trademark of UL Solutions. The circle with the letters "UL" is a registered trademark (hence the ® symbol) and may only be used by companies that have completed an official UL certification process.
This wording indicates that this is the new "UL Certified" mark. In 2013, UL consolidated the earlier regional marks (UL Listed for the USA, cUL for Canada) into the unified "UL Certified Mark." This modern mark can be recognized by the fact that it explicitly states both, the geographic scope of validity and the type of certification.
This is a two-part piece of information:
SAFETY = Certification type / category
It is a safety certification (opposed to e.g. "PERFORMANCE", "EMC" or "ENERGY").
US·CA = Geographic scope
The certification applies to the United States (UL standards UL 508A) and to Canada (CSA standards).
This is the UL File Number, a unique identifier assigned by UL to the company and the product category. Using this number, the certification can be found in the publicly accessible UL product database UL Product iQ. Anyone can verify whether the certification is valid, which products it covers, and which standards have been applied.
This is a sequential control number for the individual label. Each label is unique. This serves internal quality control and UL audits, since labels are issued in controlled quantities.
This is the product category and certification scope. In this case: enclosures for industrial control panels. The relevant UL standard is UL 508A (Standard for Industrial Control Panels). This information clarifies exactly what the certification covers. A UL label may not be transferred to other product categories.
The following tests were performed as part of the certification
Hosedown Test (water jet / spray test) Test of watertightness for Type 4 and Type 4X enclosure ratings. The enclosure is sprayed with a strong water jet from a defined distance of approximately 3 m for 5 minutes. No water may enter the interior.
5-Inch (127 mm) Flame Test - A 127 mm flame is applied directly to the finished enclosure. The test evaluates whether the material ignites, how quickly the flame extinguishes, and whether burning drips form. This test is performed on the actual finished product (not just on a material sample).
Crushing Resistance Test: The enclosure is subjected to a defined static load to demonstrate mechanical stability under pressure. No deformation may occur that would compromise the protection of the installed components.
Mold Stress Relief Distortion Test: The enclosure is exposed to elevated temperatures over a defined period. This tests whether internal stresses from the manufacturing process are present in the material that could later cause distortion.
Impact Resistance Test at room and low temperature: Impact test using a falling weight or pendulum on defined points of the enclosure. The test is performed at room temperature and after conditioning at low temperatures, since materials become more brittle in the cold.
These four tests evaluate the load capacity of the connection points for rigid metal conduits, a common installation method in North America:
Pullout Test: A defined tensile force is applied along the axis of the connected conduit. The connection must not pull out of the enclosure.Torque Test: A defined torque is applied to the connection. The test verifies whether the connection can withstand the torque applied during tightening or caused by vibration.
Bending Test: A lateral bending force (leverage) is applied to the connected conduit. This simulates what happens when an installed conduit is pulled on or bumped.
Breakout Test: This test evaluates whether, under extreme load, the conduit connection fails in a controlled manner without tearing larger parts out of the enclosure and causing an uncontrolled loss of the enclosure rating.
Which kind of benefits do the UL-approved MBI enclosures offer for you?
🚀 Faster project approvals Pre-certified components significantly simplify coordination with inspectors, integrators and end customers. Instead of having to demonstrate every detail individually, the enclosure is already qualified.
🛡️ More planning reliability Compliant enclosure solutions reduce risk throughout the project and create reliability from design to installation.
📈 Better market access in North America UL-compliant components are a fix requirement in many projects and a clear competitive advantage over non-certified alternatives in others.
🤝 Greater end-customer trust The UL mark stands worldwide for tested quality and technical safety. It signals: this is not just a promise. It is regularly verified.
The UL certification covers the entire MBI product group, including all versions.
MBI's proven strengths remain the same 💪
With all this new certification power, the well-known strengths of the MBI series naturally remain the same:
- Enclosure rating IP66 and NEMA 4X
- Seamlessly foamed-in two-component polyurethane gasket
- Temperature resistance: -40 °C to +100 °C (-40 °F to +212 °F)
- Impact resistance IK08 (DIN EN 50102:1997-09)
- Glass-fiber-reinforced polycarbonate in gray RAL 7035, alternatively black RAL 9005
- UV-resistant (UL 746C F1)
- Self-extinguishing (UL 94 V0)
- Flammability classification UL 94 V2 with transparent cover
- UL approval also available with cover hinges
- Custom machining and assembly on request
- Quality Made in Germany 🇩🇪
Make international projects easy ✈️
With the certified MBI series, you get more than "just" a high-quality industrial enclosure. You get a reliable foundation for international projects.
Get in touch 📞
Are you planning a project for the North American market or looking for an enclosure solution for demanding operating conditions? Our team will be happy to advise you on selecting the right option.