MNS Low Voltage Withdrawable Switchgear
MNS low voltage withdrawable switchgear is a modular, multi-functional power distribution system designed for applications requiring high reliability and flexibility. Manufactured by GOHO in compliance with IEC 61439-1 and IEC 61439-2 standards, the MNS switchgear is widely used in metallurgy, petrochemical, industrial and mining enterprises, power plants, and infrastructure projects for power distribution, motor control, and reactive power compensation.
The MNS series adopts a withdrawable (draw-out) unit design, allowing circuit breakers, contactors, and functional units to be easily removed for maintenance, inspection, or replacement without shutting down the entire switchboard system. The draw-out mechanism features clearly defined Connected, Test, and Disconnected positions with mechanical interlocks ensuring safe operation — a faulty unit can be withdrawn and replaced with a spare in minutes, significantly improving system uptime and operational flexibility compared to fixed-mounting alternatives.
The enclosure is constructed from cold-rolled steel plate with epoxy powder coating, with full compartmentalization between busbar, functional unit, cable, and control compartments for enhanced safety and arc fault containment.
Technical Specifications
| Item | Specification |
|---|---|
| Rated Insulation Voltage (Ui) | 660V / 1000V |
| Rated Working Voltage (Ue) | 380V / 400V / 415V / 660V |
| Rated Current (Main Busbar) | Up to 6300A |
| Rated Current (Branch Busbar) | Up to 1200A |
| Rated Frequency | 50Hz / 60Hz |
| Rated Short-time Withstand Current (Icw) | 50kA / 65kA / 80kA (1s) |
| Rated Peak Withstand Current (Ipk) | 105kA / 143kA / 176kA |
| Degree of Protection | IP30 / IP40 / IP54 (optional) |
| Enclosure Material | Cold-rolled steel / Stainless steel (optional) |
| Surface Treatment | Epoxy powder coating, RAL 7035 (standard) |
| Unit Types | Fixed / Plug-in / Withdrawable (draw-out) |
| Drawer Unit Sizes | 1/4 unit, 1/2 unit, 1 unit, 2 unit, 3 unit |
| Busbar Material | High-conductivity electrolytic copper (T2 grade) with full silver-plated contact surfaces |
| Standards | IEC 61439-1, IEC 61439-2 |
Key Features
- Modular Multi-Functional Design: Flexible combination of fixed, plug-in, and withdrawable unit configurations within a single switchboard, supporting a wide range of applications including incoming feeders, outgoing feeders, motor control centers (MCC), reactive power compensation (capacitor banks), lighting distribution, and auxiliary power supply
- High Interchangeability: Drawer units of the same specification are fully mechanically and electrically interchangeable, simplifying spare parts management and enabling rapid unit replacement — a critical advantage for continuous-process industries where every minute of downtime directly impacts production output
- Withdrawable Draw-Out Mechanism: Three-position draw-out mechanism (Connected / Test / Disconnected) with automatic shutter covering live busbar contacts when the drawer is removed, ensuring operator safety during maintenance — the test position allows functional testing of control and protection circuits without energizing the main circuit
- High Short-Circuit Withstand Capacity: Main busbar system rated up to 80kA short-time withstand current (Icw) and 176kA peak withstand current (Ipk), ensuring safe operation under the most demanding fault conditions in heavy industrial and power generation applications
- Arc Flash Protection: Compartmentalized design with physical separation between busbar, functional unit, cable, and control compartments limits arc fault energy propagation — pressure-relief flaps safely direct arc gases to designated exhaust areas
- Robust Busbar System: Main busbar rated up to 6300A using high-conductivity T2 electrolytic copper with full silver-plated contact surfaces and bolted connections, ensuring minimal temperature rise and reliable power transfer under continuous full-load operation
- Flexible Cable Termination: Generous cable compartment dimensions accommodate multiple cable entries per circuit with accessible termination points, reducing installation time and simplifying future circuit modifications
- Comprehensive Interlocking: Mechanical and electrical interlocks prevent incorrect operations including drawing-out or drawing-in the drawer while the circuit breaker is in the closed position
Applications
- Power plants — auxiliary power distribution, unit control, and motor control centers
- Petrochemical and refining — motor control, process power distribution, and emergency shutdown systems
- Metallurgy — rolling mill control, furnace power supply, and crane power distribution
- Commercial and high-rise buildings — main distribution boards, lighting control, and HVAC power
- Infrastructure — water and wastewater treatment, data centers, airports, and hospitals
- Marine and offshore — shipboard power distribution and platform auxiliary systems
- Mining — underground and open-pit mine power distribution and motor control