Air Insulated Ring Main Unit

When you're sourcing ring main units (RMUs) for your projects, practicality and long-term reliability are always top priorities-and that's exactly what Kechang's air insulated RMU delivers. We've designed this unit with cooling efficiency front and center: natural air cooling (AN) comes as standard, which works perfectly for most regular load conditions. For projects with higher load demands, you can opt for forced air cooling (AF) with quiet-running fans. The best part? It switches automatically between AN and AF modes, adjusting cooling capacity based on real-time internal temperatures. We've also tweaked the ventilation layout to boost heat dissipation by around 18% compared to standard designs-no more overheating buildup, no unexpected thermal trips. This not only keeps operations steady but also cuts down on how often you need maintenance, lowering your overall operating costs in the long run.

Reliable insulation is non-negotiable for RMUs-it's what keeps them safe and extends their service life. Our air insulated RMU uses a Class F (155°C) insulation system as the base, and we've upgraded critical components with H-class insulation materials and Nomex paper to boost thermal endurance even further. Key parts get epoxy resin casting treatment, too-this enhances insulation strength, keeps moisture out, and improves dielectric performance, all while reducing the risk of partial discharge. Even in tough operating environments, this unit holds up, delivering a service life of 25 to 30 years. We'll provide you with detailed insulation and routine test reports, so you can easily verify performance and meet all your project's compliance requirements without hassle.

Fire safety is a big concern, especially for RMUs installed in hospitals, data centers, or commercial buildings-places where even a small risk can't be tolerated. That's why we built our air insulated RMU with an oil-free structure. No oil means no leakage, eliminating the fire hazards you get with traditional oil-filled equipment. The epoxy resin we use meets F1 grade flame-retardant standards, and the unit has passed all relevant IEC and UL fire safety tests. We've also added a sealed, air-insulated design to keep external contaminants from getting inside the enclosure. All these features work together to boost operational safety and reliability, giving you peace of mind in critical installations.

If you're installing RMUs in residential areas or indoor power rooms, noise is another factor you can't overlook. We've incorporated several low-noise design tweaks to address this: optimized magnetic core structures, vibration-damping components, and those quiet fans we mentioned earlier. Depending on how you configure the unit, operating noise stays between 45 and 58 dB-right in line with IEC and GB standards. This makes it a great fit for noise-sensitive environments, so you won't have to deal with complaints from residents or operational restrictions due to excessive sound levels.

Environmental adaptability is where this RMU really stands out. You can choose protection levels up to IP44, which means the enclosure keeps dust, moisture, and corrosion at bay effectively. It's designed to run reliably in ambient temperatures from –25°C to 40°C-perfect for areas with extreme weather. It also works well in high-humidity locations and at altitudes up to 2000 meters. We've made the housing robust too, adding extra mechanical strength so it holds up in outdoor substations, industrial parks, and urban distribution networks-no matter what the environment throws at it.

Every project is different, so we don't force you into one-size-fits-all solutions. Kechang offers flexible customization options for this air insulated RMU: adjust voltage ratings, pick a capacity between 50 kVA and 2000 kVA, choose your protection level, tweak enclosure dimensions, or select wiring solutions like copper busbars or cable terminals. This flexibility means you won't run into compatibility issues with standard products-you get a unit that fits seamlessly into your existing power distribution system. All our air insulated RMUs are made to meet IEC 60076, IEEE C57, CE, UL, and RoHS standards, plus EU EcoDesign efficiency requirements. Backed by our ISO 9001 and ISO 14001 certifications, we include a three-year quality warranty, complete technical documentation, and on-site installation support. From sourcing to commissioning, we've got you covered-so you can deliver your project smoothly and reliably.