The electricity power distribution system provides the end user with electricity and is the final stage in delivering electricity. Several subsystems support it and one of which is the ring main unit. 

The ring main unit is a medium voltage of between 7200 volts to 36000 volts, assembly that is a gas-insulated unit. It is the whole switchgear in itself. When we say it is complete switchgear, it is an assembly of switching devices, protection drives, and even metering devices. 

Structure of Ring main unit

RMU is an essential component of the last phase of the electricity distribution system consisting of one incomer feeder and an outgoing feeder. The former, the incomer feeder, is generally a vacuum circuit breaker mostly linked with a disconnect and earth switches. Incomer feeders in laymen can be described as the source that feeds the bus with power coming from the transformer, which then takes it to the remote end. 

On the other hand, the outgoing feeder constitutes a load break switch associated with a disconnect switch and an earth switch. In other words, the feeder feeds itself from the electricity from the bus. It is provisioned with a connection cable. The load break switches are provided with the outgoing feeder to break the circuit in a load situation. 

Both incoming and outgoing feeders are arranged and enclosed in an SF6 environment to have a more compact design. In addition, a compatible instrument is mounted over the Ring main unit to check the gas pressure inside the RMU assembly. The concerned tool is then categorized into three or more subscales, with each subscale having two zones that are green and red. Furthermore, the breaker, disconnect switch, and earth switch have additional mechanical indicators.

Importance of Ring Main Unit

RMU is an easily replaceable switchgear unit. It also works on low maintenance and is highly protected. Another significant point of RMU is that it covers the needs and demands of the broad consumer base and is available in various voltages, equally ideal for indoors and outdoors. 

The ring main unit has a protective relaying, enabling it to act as a switching device with self-powering capabilities. To sum up, the part of the Ring main unit in the secondary distribution system provides an uninterrupted electricity supply. And depending on the loading condition and applications, it can be utilized as a circuit breaker or a switch fuse combination to protect the transformer. 

Given the range of advantages of the Ring Main Unit, the diversity of fields such as small industries, solar plants, wind power plants, and other places such as airports, hospitals, complexes, hotels, etc., use it in one form or the other.

Given the significance of RMU in the electricity distribution system, TLS Oman aims to provide a safe and optimum up gradation of the grid with the latest relevant technology with our range of services. It will ensure you can enjoy the benefits of grid connectivity without worrying about your data or any information. With reduced maintainable cost, enjoy improved energy availability with practical solutions.

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