YRM-12 Fully Insulated and Fully Enclosed Main Ring Unit Switchgear (Standardized), independently developed by our company, has been listed as a high-tech product of Zhejiang Province by China’s National High-Voltage Electrical Apparatus Testing Center in type tests and the Zhejiang Province High-Tech Technology Project. It is widely used in 10kV/6kV power distribution systems and is preferred by various urban and rural users of power distribution systems.
The switchgear is modular and can be combined for various purposes. It consists of two categories: non-expandable unit combinations and expandable unit combinations, to meet the needs of various power substations in flexible applications of compact switchgears.
YRM-12 Fully Insulated and Fully Enclosed Main Ring Unit Switchgear (Standardized) is a completely sealed system, with all live parts and switches enclosed in a stainless steel shell. The entire switchgear is not influenced by external environmental conditions, ensuring reliable operation and personal safety. It is also maintenance-free. Through an expandable bus, any combination is available, and the switchgear is fully modular. The expandable bus is insulated and shielded safely to guarantee high reliability and safety. YRM-12 inflatable switchgear can also provide TV-based automation solutions with the concept of intelligent switchgear, minimizing the work of on-site installation and commissioning.
YRM-12 Fully Insulated and Fully Enclosed Main Ring Unit Switchgear (Standardized) has both non-expandable and expandable standard configurations. Due to its fully-modular and half-modular combination and expandability, it is especially flexible.
YRM-12 Fully Insulated and Fully Enclosed Main Ring Unit Switchgear (Standardized) conforms to GB standards. Its design life is over 30 years in indoor conditions (20°C).
Item ModuleC Module F Module V Compound switch Appliance combination Vacuum switch Rated voltage kV 12 12 12 Rated frequency Hz 50/60 50/60 50/60 Power frequency withstand voltage (phase-to-phase/disconnection) kV 42/48 42/48 42/48 Lightningimpulse withstand voltage kV 75/85 75/85 75/85 Rated current A 630 Note: 1) 630/1250 Rated closed-loop breaking current A 630 Rated cable charging breaking current A 10 Rated short-circuit closing current (peak) A 50 80 Rated peak withstand current kA 50 Ratedinstantaneous withstand current kA/3s 20 Rated short-circuit breaking current kA 31.5 20/25 Rated transfer current A 1750 Maximum fuse current A 125 Circuit resistance -N ≤200 ≤400 Mechanical life time 5000 3000 5000
The fully insulated and Fully Enclosed Main Ring Unit Switchgear is a medium voltage electrical distribution solution engineered for safe, efficient, and reliable operation. Its fully insulated and enclosed design ensures high dielectric strength, operator safety, and low maintenance.
This guide provides a complete reference for installation, technical specifications, testing standards, and real-world application examples, ideal for engineers, operators, and procurement professionals.
Overview of Fully Insulated and Fully Enclosed RMU
Technical Specifications
Installation Instructions
Testing and Inspection Standards
Application Scenarios and Case Studies
Advantages and Benefits
Safety Considerations
Maintenance and Inspection Guidelines
Troubleshooting Common Issues
Certifications and Compliance
Conclusion
The main ring unit switchgear is a metal-enclosed, fully insulated electrical device designed for medium voltage ring main distribution networks. Key features include:
Full Insulation: Provides enhanced dielectric strength and reduces risk of electrical faults.
Fully Enclosed Structure: Protects internal components from dust, moisture, and unauthorized access.
Compact Modular Design: Ideal for space-constrained indoor and outdoor installations.
Reliable Switching Operation: High mechanical and electrical endurance for long-term performance.
IEC Certification: Compliant with international standards for safety and performance.
| Parameter | Specification |
|---|---|
| Rated Voltage | 12 kV / 24 kV |
| Rated Current | 630–1250 A |
| Short-Circuit Breaking Capacity | 20 kA / 25 kA |
| Insulation Type | Fully Insulated |
| Enclosure Type | Fully Enclosed Metal Cabinet |
| Installation Environment | Indoor / Outdoor |
| Mechanical Endurance | 10,000 operations |
| Electrical Endurance | 2,000 operations |
| Operating Frequency | 50Hz / 60Hz |
| Ambient Temperature Range | -40°C to +50°C |
| Protection Class | IP54 / IP65 |
| Control Mechanism | Spring or Motor Driven |
These specifications ensure high reliability and long-term service under various environmental and operational conditions.
Select a stable, level foundation with adequate drainage.
Maintain sufficient clearance for operation and maintenance.
Verify ambient temperature, humidity, and ventilation meet design requirements.
Prepare proper grounding systems according to electrical standards.
Position the RMU Cabinet according to the layout plan.
Secure the Base using bolts to ensure stability.
Connect Incoming and Outgoing Feeders following the wiring diagram.
Check Insulation Integrity: Verify insulation is intact and free from defects.
Mechanical Test: Operate switches manually to ensure smooth motion.
Functional Test: Perform no-load and load switching tests to confirm operation.
| Test Type | Requirement |
|---|---|
| Insulation Resistance Test | ≥100 MΩ |
| Contact Resistance Measurement | ≤10 μΩ |
| Mechanical Operation Test | Smooth operation for full cycle |
| Protective Relay Coordination | Proper tripping and signaling |
| Cabinet Integrity Check | No mechanical defects, proper enclosure sealing |
Dielectric Strength Test: Ensures insulation can withstand operational voltage.
Contact Resistance Test: Measures low resistance across closed contacts.
Continuity Check: Confirms all circuits are properly connected.
Operational Cycle Test: Repeated switching to verify mechanical endurance.
Interlock Testing: Ensures safety mechanisms prevent improper operations.
Humidity Resistance: Checks insulation under high moisture conditions.
Temperature Tolerance: Confirms operation within specified ambient temperature range.
IEC 62271 Series: medium voltage switchgear standard
ISO 9001: Quality management system
CE Marking: Safety and environmental compliance
RoHS Directive: Restriction of hazardous substances
Compact design allows installation in limited space.
Supports ring main distribution to residential and commercial areas.
Provides reliable electrical distribution for factories, plants, and processing units.
Reduces downtime with low maintenance requirements.
Ideal for solar farms, wind turbines, and hydroelectric plants.
Ensures safe and stable operation in outdoor environments.
Project: 24 kV ring main network in a metropolitan area.
Solution: Fully insulated and fully enclosed RMU installed in multiple substations.
Outcome: Reduced maintenance, improved safety, and reliable power distribution to over 50,000 households.
Enhanced Safety: Full insulation and enclosed design reduce the risk of electrical accidents.
Space-Saving Design: Compact dimensions suit urban and industrial installations.
Low Maintenance: Fully enclosed structure prevents dust, moisture, and contamination.
Long-Term Reliability: High mechanical and electrical endurance ensures stable operation.
Versatile Applications: Suitable for indoor, outdoor, and renewable energy installations.
Always disconnect power before inspection or maintenance.
Wear PPE, including insulated gloves, safety glasses, and protective clothing.
Avoid contact with live components.
Follow manufacturer guidelines and IEC standards during operation.
Ensure grounding and interlocks are properly installed.
| Task | Frequency | Description |
|---|---|---|
| Visual Inspection | Monthly | Check for corrosion, dust, or mechanical damage |
| Mechanical Operation Test | Quarterly | Test switch operation and interlocks |
| Insulation Condition Check | Bi-Annually | Inspect for cracks, wear, or contamination |
| Cleaning | Bi-Annually | Remove dust, dirt, and debris |
| Electrical Contact Inspection | Annually | Check for wear, pitting, or loose connections |
Tighten electrical connections to prevent overheating.
Avoid prolonged exposure to moisture and contaminants.
Monitor ambient temperature and maintain within specification.
| Issue | Possible Cause | Recommended Action |
|---|---|---|
| Switch fails to operate | Mechanical obstruction | Inspect, lubricate, and adjust mechanism |
| Abnormal voltage or current | Loose or corroded contacts | Tighten or replace connections |
| Indicator malfunction | Faulty control wiring | Check wiring, calibrate, or replace panel |
| Excessive noise during operation | Worn moving parts | Lubricate or replace components |
| Insulation degradation | Moisture, dust, or overheating | Clean, dry, or replace insulation |
IEC 62271: Medium voltage switchgear standard
ISO 9001: Quality management certification
CE Marking: EU safety and environmental compliance
RoHS Directive: Restriction of hazardous substances
These certifications ensure the switchgear meets international quality, safety, and environmental standards, making it suitable for global deployment.
The fully insulated and fully enclosed main ring unit switchgear is a reliable, compact, and durable medium voltage solution. Its full insulation, enclosed design, and IEC compliance ensure safe, efficient, and long-term operation for urban substations, industrial facilities, and renewable energy networks.
Proper installation, adherence to safety standards, and regular maintenance guarantee long-term performance, minimal downtime, and operator safety, making it an ideal choice for modern electrical distribution systems.
Phone: +8613736779975
E-mail: sales@vcbbreaker.com
Address: 66 Punan Road, Yueqing Economic Development Zone, Zhejiang, China
Copyright © 2025 Yangmei Electric Group All rights reserved
This website uses cookies to ensure you get the best experience on our website.
Español
Portugues
Pусский
العربية
Türk dili
Indonesia
Tiếng Việt
қазақ
فارسی
українська
беларускі
Filipino
o'zbek
български
тоҷикӣ
kiswahili
Монгол
አማራ
Ilocano
Phone