When a control panel at a utility substation suddenly loses its signal and the field crew can’t find anything wrong, the culprit is often stray radio energy leaking into an electrical cabinet it was never built to keep out. Situations like this are what RFI enclosures are engineered to solve.
Fralo Industries has been fabricating and assembling these enclosures for over fifty years, helping industrial companies keep their operations running smoothly. In the guide below, we compare in-depth RFI and EMI shielding enclosures so you can make an informed investment. Read the full article and feel free to give us a call with any questions about our capabilities and expertise.
How Is an RFI Enclosure Different from an EMI Enclosure?
Radio frequency interference affects the frequency bands used by wireless networks, handheld radios, and other communication devices. An RFI enclosure is conductive metal housing that stops these signals from compromising sensitive electronic systems. Tight seams and conductive door gaskets maintain shielding continuity, while filtered cable entry points prevent connected wiring from acting as an unintended antenna.
RFI refers specifically to radio frequency. Electromagnetic interference covers a broader frequency spectrum. It also includes low frequency magnetic fields generated by transformers and large motors, which conductive metal alone may not attenuate. Controlling these fields requires high-permeability that both absorb and redirect magnetic influx, so EMI shielding enclosures are typically fabricated using heavier-gauge metals and robust filtering.
The Science Behind Shielding Enclosures
The effectiveness of any EMI and RFI enclosure is measured in decibels, with each 20dB representing a one-tenth reduction in magnetic field strength. Two mechanisms are responsible for most of that protection.
Reflection bounces much of the wave’s energy back at the metal surface, like sunlight glancing off a mirror. Absorption then turns the remaining energy into heat through eddy currents inside the wall. Since a wave’s penetration depth shrinks as frequency climbs, even thin sheets of aluminum can deliver reliable shielding protection.
The result? An industrial facility with fewer interference-related disruptions, more reliable sensor readings near motor drives, and fewer intermittent faults for maintenance teams to troubleshoot. Properly engineered EMI and RFI enclosures can also contribute to compliance with applicable IEC 61000 requirements.
Why Fabrication Details Make a Difference
The reliability of EMI and RFI enclosures depend on seemingly minor fabrication details. Even the smallest seam gap can behave like a slot antenna. This is why continuous welds and tightly spaced fasteners with conductive gaskets are so crucial. Precise honeycomb waveguide vents are also essential for letting air pass while blocking radio waves.
Furthermore, enclosures need to be properly coated as paint is an insulator. Investing in trusted sheet metal fabrication and assembly can mean the difference between dependable shielding performance and costly interference-related failures.
Call Fralo Industries for Expertly Crafted EMI and RFI Enclosures
Fralo Industries fabricates and assembles custom EMI and RFI enclosures for industries with no margin for error. Reach out to our team today and tell us about the electrical equipment you need to protect against radio or other electromagnetic interference.
We’ll provide engineering support to help you find the solution that’s right for application and build it to exact specifications. From welding to machining and finishing, we have the capabilities to meet your unique requirements.