1. Product Overview
This production line provides a complete automated assembly solution for the large-scale manufacturing of ring main units (RMU), suitable for the assembly, testing, and line-off transfer of medium voltage switchgear cabinets at 10 kV and below. The RMU production line adopts a layout logic of “product moves, while personnel and workstations stay in place,” with the RGV (Rail Guided Vehicle) as the core logistics unit, combined with standard assembly workstations, in-line testing systems, and a line control system. It achieves continuous production of ring main units from gas tank loading to finished product line-off, reducing manual handling and ensuring product consistency. The RMU assembly line can be customized according to customer capacity requirements and workshop layout.
2. System Configuration
2.1 RGV Rail Guided Vehicle System
- Travels along a fixed track, carrying skids and cabinets for automatic transfer between workstations
- Photoelectric sensor arrival detection, PLC communication control, with automatic positioning and audible/visual alarms
- Rail-guided structure provides stable positioning and sufficient load capacity for full-cabinet RMU transfer
2.2 Standard Assembly Workstation Modules
- Workstations are arranged on both sides of the track, each completing a specific operation
- Typical stations: gas tank loading; installation of bushings / bursting discs / observation windows / density gauges; load switch and disconnector installation; circuit breaker installation; busbar and mechanism adjustment; secondary wiring; cabinet door installation and labeling; line-off
- Optional roller conveyor sections and lift transfer platforms for smooth transfer between the main line and workstations
2.3 Robotic Welding System
- Covers gas tank seam welding, stiffener welding, and rear cover plate welding
- Controllable welding parameters ensure consistent weld quality, reducing dependence on manual skill
2.4 In-Line Testing System
- Mechanical characteristic run-in inspection
- Comprehensive performance testing
- Power frequency withstand voltage testing
- Helium leak detection and gas filling station for SF6 gas tanks
2.5 Line Control and Information System
- PLC centrally schedules RGV and workstation operations
- Electronic Kanban boards display production progress and equipment status in real time
- Reserved MES/SCADA interfaces for order issuing, data collection, and traceability
3. Process Flow
Metal enclosure manufacturing → functional loop assembly → operating mechanism installation → insulation treatment → performance testing.
Specific takt-time flow within the line:
Gas tank loading → installation of bushings / bursting discs / observation windows / density gauges → load switch and disconnector installation → circuit breaker installation → busbar and mechanism installation and adjustment → mechanical characteristic run-in inspection → comprehensive performance testing → rear cover plate welding → helium leak testing and SF6 gas filling → gas tank insulation testing → final assembly of gas tank and sheet metal enclosure → secondary wiring and commissioning → installation of electric operating mechanisms, interlock devices, and cabinet doors → labeling and line-off.
4. Key Technical Features
- Multi-variety compatibility: supports mixed-model production of air-insulated, SF6 gas-insulated, and solid-insulated ring main units, with tooling designed for quick changeover
- Automated logistics: high-precision RGV positioning with smooth transfer, reducing heavy material handling and personnel movement
- Integrated testing: key inspection stages such as withstand voltage, run-in, and helium leak detection are all completed in-line
- Digitalized management: visualization of production progress, equipment utilization, and alarm notifications, with remote monitoring support
- Modular design: workstations can be flexibly added, removed, or expanded according to product models and capacity requirements
5. Technical Specifications (Customized per Project)
| Item | Parameter |
|---|---|
| Applicable product | Ring main unit (air / SF6 / solid insulated) |
| Rated voltage | 10 kV and below (extendable to 35 kV) |
| Cabinet weight reference | Approx. 200–1500 kg/unit (model- and configuration-dependent) |
| RGV load capacity | Designed with margin above the maximum cabinet weight; reference range 1000–2000 kg |
| RGV positioning accuracy | Customized per project (photoelectric sensor + PLC positioning) |
| Number of workstations | Per process configuration (standard / non-standard, expandable) |
| Production takt | Per customer capacity requirements |
| Control system | PLC + touch screen, optional MES integration |
| Power supply | AC 380V / 50Hz |
6. Delivery and Customization
- Custom design based on customer product drawings, capacity requirements, and workshop layout
- Optional add-ons: robotic welding, automatic helium leak detection, withstand voltage chamber, electronic Kanban, MES data interface, etc.
- Installation and commissioning, personnel training, and after-sales maintenance included
