HJ-AM Series (Air-Insulated Metal-Enclosed RMU)
Up to 24kV / Air-Insulated / Highly Customizable
The HJ-AM Series Air-Insulated Metal-Enclosed RMU is the highly reliable and economically optimized foundation for secondary medium-voltage distribution. Utilizing ambient air as the primary insulation medium combined with maintenance-free SF6 load break switches or vacuum circuit breakers, it delivers exceptional operational safety, visible fault isolation, and modular flexibility. It is the definitive cost-effective choice for standard indoor substations.
Ideal for Secondary Indoor Distribution:
- ✓ Commercial Buildings & Residential Complexes
- ✓ Light Industrial Parks & Manufacturing Facilities
- ✓ Urban Secondary Substations & Switching Stations
- ✓ Infrastructure Upgrades with Strict Budget Controls
1. Maximum Cost-Efficiency & Modularity
Optimize your project CAPEX. By utilizing ambient air as the primary insulation, the HJ-AM series provides an incredibly economical distribution solution. Engineered for global compatibility, it accommodates diverse voltage ratings (12kV to 24kV). Its top-to-bottom modular architecture ensures rapid installation, effortless maintenance, and highly flexible capacity expansions for future grid demands.
2. Compartmentalized Safety & Pressure Relief
Operator safety is engineered into the frame. The cabinet features strictly segregated compartments (Busbar, Switch, Cable, and LV Control) separated by grounded steel plates. Furthermore, dedicated pressure relief channels ensure that any rare internal arc fault gases are directed safely away from personnel.
3. Maintenance-Free Switching Cores
The main switch compartment houses a premium SF6-insulated Load Break Switch (LBS) or a dedicated Vacuum Circuit Breaker (VCB) for frequent operations. These hermetically sealed switching components are virtually maintenance-free, delivering exceptional electrical longevity and reliable arc extinguishing.
4. "5-Prevention" Mechanical Interlocks
Complying with the highest international safety standards, the switchgear is equipped with a foolproof mechanical "5-Prevention" interlocking system. This strictly prevents human misoperations, ensuring that grounding switches and cabinet doors can only be operated under absolute safe, de-energized conditions.
Integrated Low-Voltage Compartment
Unlike older models, the HJ-AM integrates a dedicated, spacious Low-Voltage (LV) compartment. This allows for the clean, organized installation of secondary components, including smart energy meters, protection relays, and SCADA communication modules, making the panel fully automation-ready.
Technical Specifications
* The parameters below correspond to standard configurations. Voltage ratings, busbar capacities, and dimensions are fully customizable to meet your local utility standards.
| Electrical Parameters | |
| Rated Voltage (Ur) | 12kV / 17.5kV / 24kV (Custom configurations available) |
|---|---|
| Rated Frequency | 50 Hz / 60 Hz |
| Rated Main Busbar Current | 630A / 1250A (Higher ratings upon request) |
| Short-Time Withstand Current (Icw) | 20kA / 25kA (3s) |
| Lightning Impulse Withstand (BIL) | 75 kV / 95 kV / 125 kV (Varies by rated voltage) |
| Power Frequency Withstand Voltage | 42 kV / 50 kV (1 min, varies by rated voltage) |
| Mechanical & Physical Properties | |
| Insulation Medium | Ambient Air (Main Cubicle) + SF6/Vacuum (Switching Core) |
| Enclosure Protection Degree | IP3X (Outer Enclosure) |
| Standard Depth (D) | 918 mm |
| Standard Width (W) | 375 mm / 500 mm / 750 mm (Depending on circuit type) |
| Standard Height (H) | 1400 mm / 1600 mm (Single-core cable) 1800 mm (Three-core cable) |
| Compliance Standards | IEC 62271-200 |
Operating Environment
- Ambient Temperature: -35°C to +45°C.
- Altitude: Standard ≤ 1000m (Consult factory for high-altitude derating).
- Relative Humidity: Daily average ≤ 95%, Monthly average ≤ 90%.
- Seismic Resistance: Withstands earthquake intensity up to 8 degrees.
- Installation Environment: Indoor, strictly free from explosive dust, severe vibration, and highly corrosive gases.
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