Air-Insulated Ring Main Units: How to Choose a Reliable Power Distribution

In today' s fast-growing power and renewable energy markets, distribution networks demand equipment that is safe, reliable, and easy to maintain. Whether you manage a utility substation, an industrial plant, or a solar-farm connection, the stability of your medium-voltage system depends on one critical piece of equipment — the Ring Main Unit (RMU).

At Zhejiang Deyan Electric Co., Ltd., we specialize in delivering Air-Insulated Ring Main Units designed for performance, longevity, and adaptability in real-world applications.

Understanding the Challenges in Medium-Voltage Distribution

Many purchasing managers and project engineers face recurring issues when sourcing RMUs:

1. Unverified Quality or Standards Compliance

Some suppliers offer low-cost RMUs that claim IEC or CE compliance but lack real type-test reports or quality assurance. This increases project risk and approval delays.

2. Maintenance Difficulties

RMUs installed in industrial or outdoor environments often face humidity, dust, and heat, which can reduce reliability if the design isn’t robust.

3. Complex Installation and Configuration

Certain RMU models are not modular or easy to expand, making network upgrades costly and time-consuming.

4. Safety Risks

Poor insulation can endanger operators and lead to unexpected downtime.

5. Limited After-Sales Support

Once equipment is delivered, some suppliers fail to provide technical guidance, documentation, or spare parts.

At Deyan Electric, we design our RMUs with these real-world concerns in mind.

How Deyan Electric’s Air-Insulated RMUs Solve These Problems

1. Certified Design and Reliable Components

Deyan Electric’s RMUs are built in accordance with IEC 62271-200, IEEE C37.60,and EN 62271-1. ensuring safe operation in 12 kV, 24 kV, and 40.5 kV networks.

Each unit undergoes routine testing and strict quality inspections in our facility in Zhejiang Province, using precision CNC fabrication and automated assembly lines.

We can provide type-test reports and documentation upon request for project verification.

2. Modular and Flexible Configuration

Our Air-Insulated RMUs feature modular panels, allowing simple expansion as your network grows. Customers can configure combinations of vacuum circuit breakers, load-break switches, fuses, and metering units to meet specific distribution needs.

3. Operator Safety First

Every Deyan RMU enclosure is designed for short-time withstand (up to 20kA/25kA/31.5kA (1 s), ensuring maximum protection for personnel during operation and maintenance.

4. Simplified Installation and Maintenance

We understand the pressure of project deadlines. Our RMUs arrive factory-assembled, fully tested, and pre-wired, reducing on-site installation time.

Because the design uses clean air insulation rather than SF₆ gas, it minimizes environmental impact and simplifies long-term maintenance.

5. Comprehensive Support and Service

From pre-sales engineering consultation to after-sales training, Deyan Electric provides end-to-end support. We offer:

    1. Detailed technical drawings and datasheets

    2. Factory acceptance testing (FAT) videos

    3. Spare parts and maintenance guides

    4. Remote or on-site assistance through our service partners