Product Overview:
The SRM-12 fully insulated enclosed Ring Main Unit (RMU) is a state-of-the-art medium voltage switchgear designed for use in 12kV electrical distribution systems. This RMU provides reliable and efficient protection, control, and distribution of electrical power. It is ideal for applications in urban and industrial power grids, ensuring the safety and stability of the electrical network.
Structural Features:
Installation Method:
Applicable Environmental Conditions:
| Content
|
Unit
|
C Module | F Module | V Module | CB Module | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Load Switch | Load Switch With Fuse | Vacuum Switch | Disconnector/ Earthing Switch | Vacuum Circuit Breaker |
Disconnector/ Earthing Switch | ||||||||||||||
| Rated Voltage | kv | 12 | 24 | 36 | 12 | 24 | 36 | 12 | 24 | 36 | 12 | 24 | 36 | 12 | 24 | 36 | 12 | 24 | 36 |
| Rated Frequency | Hz | 50/60 | 50/60 | 50/60 | 50/60 | 50/60 | 50/60 | ||||||||||||
| Power Frequency Withstand Voltage in 1 min
|
kv
|
42 | 52 | 80 | 42 | 52 | 80 | 42 | 52 | 80 | 42 | 52 | 80 | 42 | 52 | 80 | 42 | 52 | 80 |
| 48 | 58 | 85 | 48 | 58 | 85 | 48 | 58 | 85 | 48 | 58 | 85 | 48 | 58 | 85 | 48 | 58 | 85 | ||
| Lightning impulse Withstand Voltage(Peak)
|
kv
|
75 | 110 | 170 | 75 | 110 | 170 | 75 | 110 | 170 | 75 | 110 | 170 | 75 | 110 | 170 | 75 | 110 | 170 |
| 85 | 120 | 180 | 85 | 120 | 180 | 85 | 120 | 180 | 85 | 120 | 180 | 85 | 120 | 180 | 85 | 120 | 180 | ||
| Rated Current | A | 630 | Note(1) | 630 | - | 1250/630 | - | ||||||||||||
| Rated Closed Loop Breaking Current | A | 630 | - | - | - | - | - | ||||||||||||
| Rated Cable Charging Breaking Current | A | 10 | - | - | - | - | - | ||||||||||||
| Rated Short Circuit Making Current AI | Q | 50 | 80 | 50 | 50 | 63 | 63 | ||||||||||||
| Rated Peak Withstand Current | KA | 50 | - | 50 | - | 63 | - | ||||||||||||
| Rated Short Time Withstand Current | kA/3S | 20 | - | 20 | - | 25 | - | ||||||||||||
| Rated Short Circuit Breaking Current | kA | - | 31.5 | 20 | - | 25 | - | ||||||||||||
| Rated Transfer Current | A | - | 1700 | - | - | - | - | ||||||||||||
| Max.Rated current of fuse | A | - | 125 | - | - | - | - | ||||||||||||
| Loop Resistance | μ Ω | ≤300 | ≤600 | - | - | - | - | ||||||||||||
| Mechanical Life | times | 5000 | 3000 | 5000 | 2000 | 5000 | 5000 | ||||||||||||




Ring cabinet, also known as the Ring Main Unit, is a kind of transmission and distribution electrical equipment, its core components mainly include load switch, fuse, circuit breaker, current transformer, voltage transformer, instrument, protective relay and so on.
The SRM-12 RMU features a fully sealed design, ensuring that all 10kV switches and electrified bodies are sealed in a gas box made of stainless steel, providing full insulation and protection from external elements. It also has a modular design, allowing for easy combination and extension of unit modules, and is maintenance-free with a highly reliable performance 23.
The RMU should operate in ambient temperatures no higher than +40°C and no less than -40°C, with an average temperature no more than +35°C within 24 hours. It is also suitable for altitudes up to 2000m, with relative humidity and vapor pressure within specified limits, and should be installed in locations free from fire, explosion hazards, severe pollution, chemical corrosion, and intense vibration.