12kV Reliable Solid-Insulated Ring Main Unit for Ring power supply
Key attributes
| Brand | ROCKWILL |
| Model NO. | 12kV Reliable Solid-Insulated Ring Main Unit for Ring power supply |
| Rated voltage | 12kV |
| Rated frequency | 50/60Hz |
| Series | RSS |
Description
With the ongoing construction of new industrial, commercial, and institutional projects, the power distribution design for such facilities typically involves medium-to-small capacity transformers, generally rated at 1250 kVA or less.
These installations demand high long-term supply reliability, while the high-voltage switching operations are relatively infrequent. For such users, the ring main unit (RMU)—though not the most fully featured switchgear—offers the optimal cost‑effective solution for loop network applications.
At the same time, large‑scale urban development has led to the widespread construction of high‑rise buildings, with substations often located directly on the ground floor. In accordance with fire safety regulations, such substations and their associated distribution equipment must prioritise oil‑free designs. Furthermore, to maximise the efficient use of building floor space, both transformers and switchgear need to be compact.
As a result, gas‑insulated ring main units, vacuum circuit breakers (or load break switch‑fuse combinations), and dry‑type transformers have become the preferred choices for power distribution in high‑rise buildings.
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Product features
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The gas‑filled compartments are fabricated from 3 to 5 mm thick stainless steel plates, providing excellent gas tightness.
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The other compartments are made of high‑quality cold‑rolled steel sheets, designed in a modular format for easy assembly.
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Each sealed compartment is equipped with an independent pressure‑relief channel to ensure operator safety and equipment integrity.
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Degree of protection: Gas‑filled compartments: IP67; Non‑gas‑filled compartments (mechanism and cable compartments): IP4X.
Technical parameter
|
Rated voltage |
kV |
12 |
|
Power frequency withstand voltage（phase to phase/earth） |
kV |
42 |
|
Power frequency withstand voltage（Between open contacts） |
kV |
48 |
|
Impulse withstand voltage phase to phase/earth |
kV |
75 |
|
Impulse withstand voltage（Between open contacts） |
kV |
85 |
|
Rated frequency |
Hz |
50 |
|
Rated current |
A |
630 |
|
Rated short-time withstand current (4s) |
kA |
20/25 |
|
Rated peak withstand current |
kA |
50/63 |
|
Rated active load breaking current |
A |
630 |
|
Rated closed loop breaking current |
A |
630 |
|
Mechanical lifetime |
Ops |
10000 |
Normal service conditions
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Ambient temperature: –25 °C to +40 °C (with a 24‑hour average not exceeding 35°C), and with no risk of SF6 liquefaction at the lowest temperature.
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Installation altitude: Not exceeding 3000 m above sea level (for higher altitudes, consult the manufacturer).
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Humidity: Average relative humidity not exceeding 95 % daily and 90 % monthly.
Solutions for ring main unit switchgear
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Research and Optimization of Temperature Rise in 12kV Solid Insulated Ring Main UnitsThe solid insulated ring main unit (RMU) is a novel distribution equipment that integrates external solid encapsulation, insulated busbar, and compact combined unit technology. Its switches and high-voltage live components are entirely embedded in epoxy resin, which serves as the primary insulation between live parts and ground, and between phases. As an environmentally friendly alternative to SF₆ gas-insulated equipment, the 12kV solid insulated RMU offers advantages but inherently suffers from -
Comparison of SF6 Gas-Insulated Ring Main Units and Solid-Insulated Ring Main UnitsIntroductionCurrently, SF6 gas-insulated ring main units (hereinafter referred to as "SF6 RMUs") dominate the market. However, SF6 gas is internationally recognized as one of the primary greenhouse gases. To achieve environmental protection and emissions reduction, its use must be reduced and restricted. The emergence of solid-insulated ring main units (RMUs) has addressed the issues associated with SF6 RMUs while incorporating numerous new features.1 Ring Mains Power Supply and Ring Main Units -
Investing Wisely: The Compelling Life Cycle Cost of Solid Insulated Switchgear"Economy" remains paramount in power equipment procurement decisions. When it comes to Solid Insulated Ring Main Units (SIRMUs), the seemingly higher initial price often causes concern. However, a deeper analysis of their Life Cycle Cost (LCC) reveals a surprisingly compelling economic picture – it emerges as the wiser and ultimately more cost-effective choice.Initial Investment: A Misunderstood Starting PointAdmittedly, the purchase price of a SIRMU can be about 5%-15% higher than tra -
Research on Partial Discharge Detection Technology for Solid-Insulated Ring Main UnitsWith the development of urban power grids, the number of solid-insulated ring main unit (RMU) installations has continuously increased. Their operational status significantly impacts the power supply reliability of the electrical system. The consequences of failures are severe: direct damage includes damage to the protected lines and equipment, as well as power loss; indirect consequences cause widespread customer outages, disrupting daily life, production, and even social stability.Currently, t
Documentation Resource Library ring main unit switchgear
FAQ for ring main unit switchgear
The 12kV solid insulated ring main unit is medium voltage switchgear designed for ring power supply systems. It is widely selected for projects with medium and small capacity transformers under 1250kVA, such as industrial, commercial and institutional buildings. It delivers reliable and cost-effective loop network power distribution with infrequent switching operations.
The whole set of equipment enjoys long-term warranty against manufacturing defects under proper installation and normal operation. We provide technical consultation and spare parts support for global projects.
It is ideal for ring power supply and loop network distribution. It fits scenarios that require high reliability while switching operations are not frequent, commonly matched with small and medium capacity transformers.
