In medium-voltage distribution systems, the most widely used types of ring main units (RMUs) currently include SF₆ gas-insulated RMUs, solid-insulated RMUs, and eco-friendly gas-insulated RMUs. However, due to the greenhouse effect associated with SF₆ gas and the recycling difficulties of solid-insulation materials, the application of SF₆ RMUs and solid-insulated RMUs will be increasingly restricted. With the national strategy promoting carbon peaking and carbon neutrality, eco-friendly gas-insulated RMUs are expected to experience rapid development.
The HDHV series eco-friendly switchgear is a new generation of gas-insulated switchgear circuit breaker products developed in response to State Grid’s standardized RMU design requirements and the national green, low-carbon development concept. This product is mainly used in indoor and outdoor 24 kV medium-voltage distribution networks as ring main switchgear for receiving and distributing electrical energy. It fully meets the standardized technical requirements of the State Grid for RMUs. It is applicable to both side-extension and top-extension RMU configurations. More than 90% of the parts are interchangeable between top-mounted and bottom-mounted disconnector schemes, offering high stability and strong compatibility. The product fully meets all type test requirements.
| No. | Item | Unit | Circuit Breaker Unit | Load Break Switch Unit |
| 1 | Rated voltage | kV | 24 | 24 |
| 2 | Rated current | A | 630 | 630 |
| 3 | Rated frequency | Hz | 50/60 | 50/60 |
| Temperature rise test | A | 1.1 Ir | 1.1 Ir | |
| 4 | Power frequency withstand voltage (phase-to-phase &phase-to-ground/ across isolating gap) |
kV | 65/79 | 65/79 |
| 5 | Lightning impulse withstand voltage (phase-to-phase &phase-to-ground/ across isolating gap) |
kV | 125/145 | 125/145 |
| 6 | Rated short-circuit breaking current | kA | 20 | - |
| 7 | Rated short-circuit breaking operations | Times | 30 | - |
| 630A active load breaking operations | Times | - | 100 | |
| 8 | Rated short-time withstand current/ duration |
kA/s | 20/4 | 20/4 |
| 9 | Rated short-circuit making current | kA | 50 | 50 |
| 10 | Degree of protection | Enclosure | IP4X | IP4X |
| Gas tank | IP67 | IP67 | ||
| 11 | Ratedfilling pressure (at 20℃) | MPa | 0.04 | 0.04 |
| 12 | Annual leakage rate | 一 | ≤0.01%/year | ≤0.01%/year |
| 13 | Mechanical endurance | Circuit breaker/ Load break switch | Times | 10,000 |
| Disconnector | 3,000 | - | ||
| Earthing switch | 3,000 | 3,000 | ||
| 14 | Overall dimensions | Width | mm | 450 |
| Depth | 950 | 950 | ||
| Height | 2100 | 2100 |
| Top-mounted disconnector and circuit breaker panel scheme |
Bottom-mounted disconnector and circuit breaker panel scheme |
||
 |
 |
||
| Cabinet Width | 450mm | Cabinet Width | 450mm |
| Cabinet Depth | 950mm | Cabinet Depth | 950mm |
| Cabinet Height | 2100mm | Cabinet Height | 2100mm |
| Load Break Switch Cabinet Scheme | Compact design | ||
 |
 |
||
| Cabinet Width | 450mm | ||
| Cabinet Depth | 950mm | ||
| Cabinet Height | 2100mm | ||
Ambient air temperature: maximum +40°C, minimum –50°C;
Relative humidity: daily average ≤95%, monthly average ≤90%;
Altitude ≤1500 m (under standard gas-filling pressure);
Seismic intensity not exceeding Grade 8;
The installation site shall be free from fire, explosion, severe pollution, chemical corrosion, or severe vibration.
For service conditions different from normal operation, agreement must be reached between the manufacturer and the end user.
If the equipment is intended for extremely harsh operating environments, the manufacturer or supplier must be consulted.
When electrical equipment is installed at altitudes above 2000 m, this must be clearly stated so that the gas tank structure can be adjusted during manufacturing.
GB/T 11022 — Common technical requirements for high-voltage switchgear and controlgear
GB/T 3906 — AC metal-enclosed switchgear and controlgear for rated voltages of 3.6–40.5 kV
GB/T 3804 — High-voltage AC load switches
GB/T 1985 — High-voltage AC disconnectors and earthing switches
GB/T 1984 — High-voltage AC circuit breakers
GB/T 4208 — Degrees of protection provided by enclosures (IP Code)
When placing an order, the user shall provide the following technical information:
Primary circuit diagram, arrangement diagram, and floor plan;
Secondary circuit schematic diagram of the switchgear;
Special environmental conditions for the switchgear (if applicable);
Specify whether a top-mounted or bottom-mounted disconnector scheme is required;
For gas tank orders, indicate whether top extension or side extension is required;
Other accessories as listed in the order options table.
 Switchgear.jpg)
English
Pусский
Español