How to Pass NEC or AHJ Inspections for Remote DC Power Applications
Industrial and commercial installations increasingly depend on distributed DC power to run automation equipment, AV systems, IoT devices, and motor control systems. Getting those systems through an electrical inspection is where projects typically stall.
For in-building applications, passing an Authorities Having Jurisdiction (AHJs) Inspection or satisfying NEC (NFPA 70) requirements typically means every power supply must be properly enclosed and agency listed. Enclosed AC/DC power supplies are a practical choice on the job; they are widely available and cost-effective. But their exposed high-voltage terminals create a real compliance problem. Without a listed enclosure, there is no clean path through inspection.
Figure 1 is an example of a non compliant installation of what an AHJ actually sees when they walk into an unlisted installation: exposed AC terminals at the bottom left, no documented thermal management, no grounding path, no enclosure and no Agency listing mark.
Figure 1 - Example Of A Non Compliant Remote Power Installation
The workaround most installers fall back on, adapting a generic box or fabricating something in the field, rarely holds up under scrutiny. Non-agency listed assemblies can trigger re-inspection, project delays, and liability exposure. Some installers were fortunate to have found ETL Listed enclosures from TRC. In those instances, our power specialists have been successful in guiding installers to matched power supplies and enclosures to ensure full certification.
Field-assembled enclosures rarely survive inspection. When an installer adapts a generic box or fabricates something on site, there is no agency listing, no documented short-circuit current rating, and no thermal baseline. NEC Article 409 requires any industrial control panel assembly to carry a marked short circuit current rating (SCCR) and be constructed to the listing standard. A field-built box may not work. NEC Article 110.10 compounds the issue by stating that overcurrent protective devices must be selected and coordinated for the available fault current at the point of installation. Without a listed enclosure that documents those values, the AHJ has nothing to reference and the job stops.
We have watched this play out many times. An installer calls after the job gets flagged for exposed AC terminals, inconsistent grounding, no listing mark on the enclosure. The rework at that stage costs significantly more than specifying it correctly before the first wire is pulled.
A UL 508A or ETL 508A listed enclosure, factory-paired with specified internal power supplies, arrives marked with safety logos, clearances verified, and grounding path defined. The inspector has a clear compliance reference. This means faster sign-off, fewer callbacks, and no failures that show up after the job is closed.
That is what the MOLTO-FLEX Remedies
Introducing the MOLTO-FLEX Family of Enclosures
If you have ever spent time in the field trying to make an open frame power supply fit a box that was never designed for it, the MOLTO-FLEX was built for you.
The standard off the shelf models ship with a mounting plate sized for the LRS 350, 450, and 600 series power supplies. If your application calls for multiple supplies or a different form factor, TRC can configure the right plate for that. The point is you are not fabricating anything on site or drilling your own pattern into sheet metal.
Figure 2 shows the two mounting versions. The recessed model drops into a wall cavity and sits flush, which is the right call for new construction or any application where the enclosure needs to disappear into the wall. The surface mount model bolts to the wall face and works better for accessible installs where someone will be coming back to service it.
Figure 2- MOLTO-FLEX Mounting Versions
What the MOLTO-FLEX Offers
The MOLTO-FLEX includes several contractor-focused features that reduce installation time and eliminate guesswork in the field.
Standard NPT knockouts are located on the top, bottom and sides of the enclosure to simplify conduit entry and cable routing. Integrated keyhole mounting slots allow for faster wall or panel mounting, and the included hardware kit provides mounting brackets, grounding hardware and cable holders.
Figure 3- MOLTO-FLEX Contractor Ready Features
Surface mount models have a switched and fused IEC 320-C14 inlet already integrated, so the AC input side is straightforward. Recessed models are hardwired, which makes sense for flush mount applications where a plug-in inlet is not practical. Both versions are available in 6 output or 15 output configurations, prewired and ready to accept the specified power supply. You are not building this from scratch on site.
Addressing Compliance and Inspection
One of the most impactful benefits of the MOLTO-FLEX is its ETL Listing to UL508A when used with the specified power supplies.
Instead of relying on enclosures with uncertain compliance outcomes - installers can integrate a pre-evaluated enclosure solution designed specifically for power integration. This provides inspectors with a clearer evaluation criteria and greatly reduces any ambiguity.
Grounding points, mounting provisions and internal layout constraints are already defined within the enclosure system, which removes a significant amount of interpretation during installation.
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Faster Inspections
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Reduced Rework - Fewer Installation Delays
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Improved Consistency Across Projects
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Lower Overall Risk
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Standard models of the MOLTO-FLEX are rated to 40℃ temperatures up to 520W of continuous power, and to 35℃ for power supplies operating at 600W.
MOLTO-FLEX Expansion Possibilities
Beyond the standard stock models, the MOLTO-FLEX supports DIN rail integration and specialized driver plate layouts, giving system designers the flexibility to standardize power architectures across a wide range of applications. TRC's value-added capabilities mean these configurations are available without the cost or complexity of a fully custom solution. Figure 4 illustrates a few examples of the possible configurations.
Figure 4- Expansion Possibilities
References:
Intertek. "Understanding AHJ Approval." Intertek Blog, December 16, 2025. www.intertek.com/blog/2025/12-16-understanding-ahj-approval.