Air Insulated RMU
Meet and Exceed your Expectations: Experience unmatched reliability, durability, scalability, and customizability.
- ODM/OEM Solutions
Tailored to your needs
Whether you need a little tweak or a total redo of Air Insulated RMU, we’ve got you covered with a custom solution. From the busbar configurations to the protection relays to the circuit breaker settings, every single piece can be customized to make your system run better and more reliably. You can customize:
- Cabinet size
- SF6 load switch
- Base
- Your logo
- Panel language
- Insulator
We’ll give you FREE 2D/3D drawings to approve before we start building anything so you can make sure we got it right.
Auxiliary transformer panel
1 of 5Bus bar lift unit
2 of 5Incoming panel
3 of 5PT cabinet
4 of 5Outgoing panel
5 of 5Air Insulated RMU Parameters
| Parameter name | Significance |
|---|---|
| Rated voltage, kV. | 6; 10; 20 |
| Highest operating voltage, kV. | 7,2; 12; 24 |
| Rated current, A: | |
| — busbars | 630; 1000; 1250 |
| — line terminals | 630; 1000; 1250 |
| — fuses | no more than 200 |
| — circuit breakers | 1000; 1250 |
| — load switch | 630 |
| — disconnectors | 630; 1000; 1250 |
| Rated current of current transformers, A | 50–1250 |
| Rated tripping current of circuit breakers, kA. | 20 |
| Rated tripping current of fuses, kA: | not more than 200 |
| — with rated current not exceeding 160 A | 63 |
| — with rated current 200 A | 50 |
| Ternary resistance current at duration of flow of 3 s, kA | 20 |
| Electrodynamic resistance current, kA | 51 |
| Normed parameters of the load breakers switching current, kA: | |
| — highest peak | 31,5; 40; 51 |
| — initial effective value of the periodic component. | 12,5; 16; 20 |
| Rated voltages of control circuits and auxiliary circuits, V: | |
| — at direct current. | 24; 48; 100; 220 |
| — at alternating current. | 220 |
| — lighting circuits | 220 |
| Operating voltage range (in percent of rated voltage): | |
| — trip solenoid circuits: | |
| DC | 24; 48; 110; 220 |
| AC | 220 |
| — for other control and signaling purposes: | |
| DC | 24; 48; 110; 220 |
| AC | 220 |
| Standards of testing of insulation of the main current-carrying circuits with one-minute voltage of 50 Hz frequency, kV: | 30:42; 68 |
| Own switching-on time, s, not more: | |
| — power circuit breakers | 0,1 |
| — motor-driven load disconnectors | 9,0 |
| — load circuit breakers with electromagnetic actuator | 0,1 |
| Own tripping time, s, not more: | |
| — circuit breakers | 0,04 |
| — motor-driven load disconnectors | 9,0 |
| — load circuit breakers with electromagnetic trip | 0,1 |
| Overall dimensions, mm: | |
| — width | 300; 500; 750 |
| — depth | 840 |
| — height: | |
| dimension 1 (without base, with removable relay protection compartment) | 2150 |
| dimension 2 (without 100 mm base, with removable relay protection compartment) | 2210 |
| dimension 3 (with 100 mm base, with removable relay protection compartment) | 2235 |
| Degree of protection according to GOST 14254. | IP3X |
| Service life before decommissioning, years, at least | 30 |
The Ultimate Guide of Air Insulated RMU
Chapter 1
What is Air Insulated RMU?
Chapter 2
Key features of Air Insulated RMU
Chapter 3
Components of Air Insulated RMU
Chapter 4
Advantages of Air Insulated RMU
Chapter 5
Applications of Air Insulated RMU
Chapter 6
Installation of Air Insulated RMU
Chapter 7
Maintenance of Air Insulated RMU
Chapter 8
What is the difference between Air Insulated RMU and Air Insulated Switchgear?
Chapter 9
Who is the manufacturer of Air Insulated RMU?
Chapter 1
What Is Air Insulated RMU?
Air Insulated Ring Main Unit (RMU) is a type of electrical switchgear used to distribute medium voltage electricity. You’ll typically find them in compact, urban, or building settings where space is tight. The “ring main” part of the name refers to its configuration in a ring network where you can connect and disconnect each circuit using load break switches and circuit breakers.
An Air Insulated RMU uses air as the insulation medium between electrical components and to extinguish arcs that occur during switching operations. This is different than Gas Insulated Ring Main Units (GIS RMUs) that use SF6 gas for insulation.
The Air Insulated RMU is typically used in configurations that include load break switches, circuit breakers, earth switches, and metering units. The main advantage of air insulated units over gas insulated units is that they do not use SF6, which is a potent greenhouse gas.
Chapter 2
Key Features Of Air Insulated RMU
Insulation and Safety: Air Insulated RMUs use air as the insulation medium, which is naturally abundant and does not require additional chemical treatments or handling precautions like SF6 (sulfur hexafluoride). This makes them environmentally friendly and safer to handle in terms of toxicity and flammability.
Reliability: These units are known for their high reliability in different environmental conditions. Air doesn’t break down as easily as other insulating materials, so you don’t have to do as much maintenance and the units last a long time.
Compact Design: Air Insulated RMUs are designed to be compact. This makes them suitable for use in areas with limited space, such as cities or inside existing buildings where space is tight.
Modular and Flexible Configuration: They typically offer flexible configurations, enabling them to be tailored to specific network requirements. This modularity allows for future expansion or reconfiguration as the network grows or changes.
Easy Maintenance and Operation: Air insulated units generally have lower maintenance requirements because air does not degrade over time like other insulating materials. They also typically have simple mechanical operation, which makes them more reliable.
Cost-Effectiveness: Air Insulated units are usually more cost-effective than Gas Insulated RMUs when it comes to initial capital investment. They also have lower lifetime costs due to minimal maintenance needs and the fact that you don’t have to deal with gas.
Compliance with Standards: These units are designed to meet international standards such as IEC 62271-1 for high-voltage switchgear and controlgear to ensure compatibility and safety in a wide range of applications.
Chapter 3
Components Of Air Insulated RMU
Circuit Breakers: These are used to keep the electricity from flowing through the network when something goes wrong or when you need to work on the system. They are critical to keeping your RMU and the rest of your system from getting fried when too much electricity goes through them.
Load Break Switches: These switches can interrupt the load current and are used for switching smaller currents than circuit breakers. They are commonly used for isolating sections of the network for maintenance or fault isolation.
Earth Switches: These provide grounding to the network components during maintenance, ensuring safety by preventing accidental energization.
Busbars: These are thick strips of copper or aluminum that conduct electricity within the RMU, connecting things like circuit breakers and switches.
Protection Relays: These are the guys that protect your system. They prevent your equipment from blowing up when it’s overloaded, shorted, or something bad happens. They make sure your system is safe and reliable by telling the circuit breaker to trip when something goes wrong.
Control and Monitoring Equipment: This means meters and sensors to see how much voltage, current, and power quality you have on your system. You might also have communication modules to allow you to monitor and control your RMUs from a remote location.
Fuses: In some cases, you might have fuses to protect the transformers connected to the RMU, providing a little extra protection against overcurrents.
Housing and Enclosure: The whole RMU is housed in a tough box that protects the guts from the weather and from people who don’t need to be in there. You usually see these boxes made out of materials that are okay to put outside, like stainless steel or some kind of plastic that’s got some glass fibers in it.
Chapter 4
Advantages Of Air Insulated RMU
Reliability and Durability: Air Insulated RMUs are built tough. They can withstand harsh environments, including extreme heat and humidity. These units are very reliable because they are simple and robust.
Safety: Safety is a big deal when it comes to designing electrical distribution equipment. Air Insulated RMUs have great safety features. The insulation and breaking happen in air, so there’s no chance of gas leaking like you’d get with gas-insulated switchgear. This is especially important in urban and environmentally sensitive areas.
Maintenance: Air Insulated RMUs require less maintenance compared to gas-insulated units. Because the insulation and interruption medium is air, there is no need for gas handling, monitoring, or refilling activities, which are necessary for SF6 gas-insulated switchgear. This reduces maintenance complexity and costs.
Cost-Effectiveness: In terms of initial investment, air-insulated RMUs are generally more cost-effective than gas-insulated alternatives. The simpler design and absence of expensive gases make them more economical to manufacture and purchase.
Flexibility and Scalability: Air Insulated RMUs can be easily expanded or reconfigured to meet changing network requirements. This flexibility allows utilities and industries to adapt their systems as their electrical distribution needs change without spending a lot more money.
If you have any more specific queries or need advice tailored to your particular situation, feel free to ask!
Chapter 5
Applications Of Air Insulated RMU
1. Urban Distribution Networks
- Application: Air Insulated RMUs are widely used in urban electrical distribution networks because they take up less space than gas-insulated solutions. Their modular design and high reliability make them ideal for fitting into compact secondary substations or street kiosks often found in urban settings.
- Standard Reference: IEC 62271-1 covers the general requirements for medium voltage switchgear and can help you with the specifications for urban applications. You can talk to our sales people on the phone or email them in Russian.
2. Industrial Complexes
- Application: In industrial complexes, it’s important to keep the power on all the time. Air Insulated RMUs disconnect the fault quickly, protect equipment, and keep the plant running.
- Standard Reference: IEC 62271-200 is the standard for metal-enclosed switchgear, which is what you need to use in an industrial environment.
3. Renewable Energy Integration
- Application: As renewable energy sources such as wind farms and solar panels increase, Air Insulated RMUs are used to connect these sources to the main grid. They manage the variable outputs and make sure everything is safe under different electrical loads.
- Standard Reference: IEC 61439, which deals with low-voltage switchgear and controlgear assemblies, might also be considered when integrating renewable sources at a lower voltage level.
4. Secondary Distribution Networks
- Application: Air Insulated RMUs are good for secondary distribution networks because you can hook up a bunch of feeders to them and they’re easy to run and fix. They’re also good for breaking load and making load.
- Standard Reference: IEC 62271-103 is the standard for switches for voltages over 1kV up to and including 52 kV, which applies to load break switches in RMUs.
5. Infrastructure Projects (Airports, Railways)
- Application: Big infrastructure projects need to have electricity delivered to them. Air Insulated RMUs are used to do that because they are tough enough to handle the environment and the amount of electricity needed.
- Standard Reference: IEC 62271-105 covers switch-fuse combinations.
6. Compact And Modular
- Application: When space is at a premium such as in urban areas or in pre-fabricated substations, Air Insulated RMUs are the preferred choice. They are known for being small and modular allowing them to be easily expanded or changed as the network evolves.
- Standard Reference: The modular aspect usually refers back to IEC 62271-1 for general specifications to make sure they meet safety and performance standards.
Chapter 6
Installation Of Air Insulated RMU
Site Preparation:
- Ensure that the installation site is clean, dry, and free of any debris.
- The area should have sufficient space for installation and future maintenance activities.
- Check for proper environmental conditions; typically, air insulated RMUs are suited for indoor environments unless specified for outdoor use.
Unpacking And Inspection:
- Carefully unpack the RMU and inspect for any visible signs of damage incurred during transit.
- Verify all components against the delivery checklist to ensure nothing is missing.
Placement And Positioning:
- Position the RMU in its designated location. Ensure that it is level using precise leveling tools.
- For outdoor installations, make sure that the unit is placed on a raised platform if required and is well-protected against direct sunlight, rain, and flooding.
Electrical Connections:
- Follow the schematic diagrams provided for electrical connections. Make sure all wiring is according to IEC standards and local regulations.
- Use proper cable lugs and ensure that all connections are tight and secure to avoid any arcing or heating.
Grounding:
- Establish a reliable grounding system to protect against electrical faults. The grounding resistance should comply with local safety standards.
- Connect the grounding cables to the designated grounding points on the RMU.
Testing Before Energizing:
- Perform insulation resistance tests to ensure that there are no electrical leakages.
- Conduct a mechanical operation test to check the functionality of all moving parts and switches.
- Optionally, carry out a high-potential (Hi-Pot) test to confirm the insulation integrity under high voltage conditions.
Commissioning:
- Once all tests are satisfactory, the unit can be energized under controlled conditions.
- Monitor the system’s initial performance to ensure everything operates as expected.
- Check all indicators and control functions to confirm they are working correctly.
Documentation And Training:
- Document all installation and testing activities. Maintain records for future maintenance and auditing purposes.
- Provide training to the operational team on safe handling, operational procedures, and emergency response strategies.
Regular Maintenance:
- Schedule periodic inspections and maintenance to ensure reliable operation of the RMU.
- Check for any signs of wear and tear, corrosion, or other potential issues that could affect the unit’s performance.
Chapter 7
Maintenance Of Air Insulated RMU
1. Routine Inspection:
- Visual Inspection: Regularly check for any signs of physical damage, corrosion, or accumulation of dust and dirt. The presence of vermin and the condition of gaskets and seals should also be checked to ensure that they are intact and functioning properly.
- Mechanical Operation Tests: Perform manual operations to ensure that all mechanical parts are functioning smoothly without any undue resistance or noise.
2. Electrical Testing:
- Insulation Resistance Testing: This test should be carried out annually to ensure that the insulation properties are within safe operating limits.
- Contact Resistance Test: Conduct this test to ensure that the contacts within the RMU are not excessively worn and are still providing a good electrical connection.
- Protection Relay Testing: Regular testing of protection relays is crucial to ensure they are functional and set correctly according to the system parameters.
3. Cleaning:
- External Cleaning: Use a dry or slightly damp cloth to clean the exterior surfaces of the RMU.
- Internal Cleaning: It’s advisable to conduct a more thorough cleaning of the internal components periodically, using non-conductive cleaning agents and tools. This is typically carried out during planned downtimes.
4. Lubrication:
- Lubricate Moving Parts: Periodically lubricate all mechanical moving parts to prevent stiffness and wear. Use only the lubricants recommended by the manufacturer to avoid any potential incompatibility with the materials.
5. Environmental Checks:
- Check for Humidity and Temperature: Ensure that the environment in which the RMU is installed adheres to the manufacturer’s specifications. Excessive humidity and temperature can adversely affect the unit’s performance and lifespan.
6. Documentation And Record Keeping:
- Maintain Records: Keep detailed records of all maintenance activities, tests results, and any replacements or upgrades. This documentation is vital for troubleshooting and future maintenance planning.
7. Training And Safety:
- Training: Ensure that all personnel involved in the maintenance of the RMU are properly trained and aware of safety procedures.
- Safety Equipment: Use appropriate safety equipment and isolation procedures to ensure that maintenance work is carried out safely.
Chapter 8
What Is The Difference Between Air Insulated RMU And Air Insulated Switchgear?
1. Configuration
- Air Insulated RMU: Typically, a compact unit designed to be used in ring distribution networks. RMUs are usually configured in a ring system, where each unit is capable of connecting to multiple sources and loads. This setup is ideal for ensuring reliability and redundancy in the distribution network.
- Air Insulated Switchgear: AIS is generally used for primary distribution and is not as compact as RMUs. It comprises multiple panels, each containing switches, circuit breakers, and other components, and can be customized to suit specific requirements. AIS is used in both ring and radial network configurations.
2. Application
- Air Insulated RMU: More commonly used in secondary distribution networks, such as residential areas, small industries, and commercial buildings where space is at a premium. RMUs are also utilized for their ease of maintenance and installation.
- Air Insulated Switchgear: This is used in higher voltage applications, including primary distribution networks and large industrial plants. AIS handles higher power loads and is suitable for both indoor and outdoor installations.
3. Size And Space Requirements
- Air Insulated RMU: Smaller and more compact, designed to fit in constrained spaces. The compact nature of RMUs makes them ideal for urban distribution networks where space is limited.
- Air Insulated Switchgear: Larger and requires more space, primarily due to its capability to handle higher voltages and currents, necessitating larger clearances and insulation.
4. Accessibility And Maintenance
- Air Insulated RMU: Generally designed for easier accessibility and less frequent maintenance. Many modern RMUs are also equipped with remote monitoring and control capabilities, reducing the need for physical inspection.
- Air Insulated Switchgear: Requires more regular maintenance given its complexity and the critical nature of the high-voltage networks it serves. Maintenance can be more time-consuming and complex compared to RMUs.
5. Cost Implications
- Air Insulated RMU: Typically less expensive than AIS due to its smaller size and simpler design. The cost-effectiveness also extends to installation and maintenance.
- Air Insulated Switchgear: More expensive initially due to its larger size, more complex design, and greater material requirements. However, it is essential for handling higher capacities and voltages, which justifies the investment.
6. Safety And Reliability
- Both types of switchgear are designed to high safety standards, particularly with regard to their operation and maintenance. However, AIS may require additional safety protocols due to its higher voltage operations.
Understanding these differences can help you choose the right equipment for your specific electrical distribution needs. If you have more detailed requirements or need advice on specific products, let us know!
Chapter 9
Who Is The Manufacturer Of Air Insulated RMU?
IE-Supply is the manufacturer of Air Insulated RMU with SF6 load switch, it mainly exports to Russia and other CIS countries. Our products are designed to meet the needs of our customers who are in high demand industries and we have customers like the State Grid Corporation of China, China Southern Power Grid, CHINT, and ABB.
IE-Supply has three production lines Air Insulated RMU. We understand that you have different needs than other people. That’s why we offer customization. You can give us your drawings and tell us what you want, and we’ll make it for you. As part of our customization service, we provide free 2D and 3D drawings for you to approve before we start making your order.
We are committed to delivering quality and value. Our partnerships with industry leaders demonstrate our dedication to quality and value. We guarantee on-time delivery to ensure your projects stay on track. Discover how IE-Supply can revolutionize your electrical infrastructure projects.
We Are Just A Phone Call Away.
You’ll have no problem talking to our sales team who speak Russian. They’ll understand exactly what you want and make sure you get it, which will make everything go faster and smoother.
- +86 135-8775-1570
- info@ie-supply.com