Modernise your grid with the smart ring main unit (RMU)
The ring main unit is a compact, fully enclosed, factory-built cabinet designed for medium voltage (MV) power distribution. This switchgear unit is straightforward to replace, requires minimal maintenance, and offers high levels of protection. To cater to varied needs, RMUs come in different voltage options, making them suitable for both outdoor and indoor applications. At Schneider Electric, we bring advanced technology and innovation to your grid through our exclusive range of smart ring main units, ensuring safety and efficiency in upgrades.
Seamlessly integrated with the PowerLogic T300 remote terminal unit (RTU) and our innovative conditional monitoring sensors, the smart RMU is an innovative solution that makes it easier for you to answer the evolving challenges of electrical distribution. As an all-in-one solution, the smart RMU is easy to purchase, install and maintain, helping to reduce operational costs. Its robust design fits even the harshest environments.
A smart RMU is an advanced version of the traditional Ring Main Unit, designed for MV distribution networks. While a conventional RMU provides basic switching and protection functions, a smart RMU integrates digital technologies such as advanced analytics, remote monitoring, automated fault detection, and grid reconfiguration. It is typically equipped with sensors, communication modules, and remote terminal units (RTUs), enabling real-time data acquisition and integration with smart grid platforms.
Smart RMUs offer a range of digital functionalities, including:
• Remote control and monitoring via SCADA systems and RTUs like PowerLogic T300.
• Condition monitoring using thermal sensors, partial discharge sensors, and predictive analytics.
• Cybersecurity compliance with standards such as IEC 62351 and IEEE P1686.
• Automated fault isolation and power restoration, reducing outage times and improving SAIDI metrics.
• Integration with distributed energy resources (DERs) and support for grid decarbonisation and decentralisation.
Smart RMUs bring several advantages:
- Enhanced reliability through looped network configurations and advanced monitoring, protection, control and automation functions thanks to RTU usage.
- Reduced operational and maintenance costs due to predictive maintenance and fewer manual interventions.
- Improved energy efficiency and load management via advanced analytics available in RTU.
- Environmental sustainability, especially with SF6-free usage.
- Improve energy availability with a cost- and time-effective solution (SAIDI).
RM6
Learn more about our 2,000,000+ modules with installed MV ring main unit.
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Ringmaster
Find out more about our MV ring main units for outdoor applications.
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PowerLogic T300
Discover a powerful Remote Terminal Unit (RTU) for feeder automation.
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Discover how digitisation, decarbonisation, and decentralisation are transforming the energy world.
Condition monitoring of ring main units (RMU)
Find out how an effective asset management and capital improvement program aims to pinpoint the exact location of the distribution network needing maintenance and repair, without the guesswork.
Why choose smart RMU
Faster power restoration thanks to decentralised schemes
Compliance with the latest cybersecurity standards
Expertise of the RMU market leader with +2.5 M installations worldwide
Smart RMU Connected Enabled
Our entry-level offer will help you improve everyday equipment maintenance and reduce OpEx costs. It features wireless thermal sensors and a smartphone app to replace infra-red thermal scanning. It also enables early detection of conditions that can result in electrical connection failures, fires, arc flashes, or worse.
Smart RMU Connected Advanced
Discover our fully-optimised and integrated, advanced-level offer for controlling, metering, condition monitoring, and fault detection. Reduce operation and maintenance expenditures, and optimise your networks for increased demand. This advanced solution is available for RM6, FBX and Ringmaster.
What is a Ring Main Unit?
Ring Main Unit (RMU) is a medium voltage, gas-insulated, fully sealed cabinet used to measure, connect, and integrate transformer protection functions with a fixed type breaker. Ring Main Units are safe, reliable, low-maintenance, and easy to replace switchgear. Depending on the user's needs and requirements, RMUs are available in many voltages, suitable for both outdoor and indoor installations. At Schneider Electric, we help you modernise your grid with innovation and digitisation with our Ringmaster Active+ range.
Improve energy availability
Reduce outage time by detecting faults early and automatically reconfiguring the network afterwards. Integrate intermittent and distributed generation smoothly to maintain energy quality and stability.
Optimise network performance
Get your grid ready for growing energy demand. With advanced analytics, you can optimise asset management, manage load shedding and peak shaving, and reduce technical and non-technical losses.Why choose our Ringmaster Active+
- Enjoy the advantages of grid connectivity without worrying about the security of your data. The smart RMU is compliant with IEC 62351, IEEE 1686 role-based access control (RBAC) and Achilles Practices.
- Benefit from reduced maintenance costs with smart sensors for substation monitoring.
- Improve energy availability with a cost- and time-effective solution (SAIDI).
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What is the function of a Ring Main Unit (RMU)?
A ring main unit consists of three switches, two inputs with the electrical interlock and one going out to the load. It is used in an electrical distribution system for an uninterrupted power supply. Furthermore, it offers effective protection to the side transformer from transient currents.
Schneider Electric UK’s smart ring main unit (RMU), with its innovative conditional monitoring sensors, offers an effective solution for you to stay in tune with the evolving confrontations in electrical distribution. The smart RMU is seamless to purchase, install, and maintain. The design offers unparalleled outdoor durability.
Why is Ring Main Unit (RMU) required?
A ring main unit is essential to monitor faults and automatically reconfigure the network post-detection. It maintains the stability and quality of the energy to improve the overall energy availability. Moreover, RMU optimises the network performance to allow your grid to stay in sync with the increasing energy demands. Advanced analytics enable an RMU to optimise asset management, minimise technical and non-technical losses, and manage peak shaving and load shedding.
At Schneider Electric UK, our smart ring main unit assures the protection of your data and is compliant with IEC 62351, IEEE 1686 role-based access control (RBAC) and Achilles Practises.