MNS Withdrawable Low-Voltage Switchgear Assembly
Overview
The MNS withdrawable low-voltage switchgear assembly is a high-end low-voltage power distribution system compliant with international/domestic standards such as IEC 61439 and GB 7251. It adopts a modular drawer-type design and is widely used in industrial and mining enterprises, data centers, commercial buildings, and infrastructure. It serves for power conversion and control of power-consuming devices in AC 50-60Hz distribution systems with rated operational voltages up to AC 660V, providing users with a safe, flexible, and intelligent low-voltage power distribution solution.
Brief Introduction
Ⅰ.Distribution introduction
1. Rated Voltage: AC 380V/660V
2.Rated Current: Horizontal Busbar ≤ 6300A, Vertical Busbar ≤ 1600A
3.Short-Time Withstand Strength: 50kA/1s (Peak)
4.Drawer Capacity: 8E/4E/2E/1E (Standard Modules)
5.Applicable Standards: IEC 61439, GB 7251
6.Protection Degree: IP30, IP40
Ⅱ.Applicable Conditions and Scope
1.Ambient Air: Temperature not higher than +40°C, not lower than -5°C, and its average temperature within 24 hours not higher than +35°C.
2.Atmospheric Conditions: Clean air, relative humidity not exceeding 50% at the maximum temperature of +40°C, allowing higher relative humidity at lower temperatures, such as 90% at +20°C, but temperature changes should be considered, and condensation may occasionally occur.
3.Altitude not exceeding 2000m.
4.If the above conditions cannot be met, the user shall negotiate with the manufacturer for a solution.
5.When used for offshore oil drilling platforms or nuclear power plants, a separate technical agreement shall be signed.
Ⅲ.Component Inspection
1. Drawer mechanical operation life test ≥ 10,000 insertion/extraction cycles without jamming.
2.Busbar connection point temperature rise test.
3.Power frequency withstand voltage test (3500V/1min, no breakdown or flashover).
Product Features
Ⅰ.Feature Introduction
1. Standardized Modules: 25mm modular design allows highly flexible combination of functional units.
2.Withdrawable Structure: All functional units can be directly withdrawn for convenient and efficient maintenance.
3.Compartmentalized Isolation: Horizontal busbar compartment, functional unit compartment, and cable compartment are completely isolated, protection degree up to IP54.
4.Five-Protection Interlocking: Comprehensive mechanical and electrical interlocking ensures operational safety.
5.Grounding System: Independent PE and N grounding systems.
6.Arc Protection: Passed internal arc fault test (IAC AFLR).
Ⅱ.Product Advantages
1. Fully Isolated Design: Each functional unit is completely independent and does not affect others.
2.High Protection Degree: Internal compartment protection degree reaches IP54, ensuring operational safety.
3.High-Quality Components: Uses internationally renowned brand components for stable and reliable performance.
4.Drawer-Type Design: All functional units can be directly withdrawn, allowing maintenance without power outage.
5.Intelligent Monitoring: Real-time monitoring of operating status, early warning of potential faults.
6.Clear Labeling: Clear identification for each unit with detailed operation instructions.
Ⅲ.Benefits Provided by the Product
1. Rapid Fault Handling: Drawer-type design reduces fault handling time by 80%.
2.High Power Supply Continuity: Faulty units can be replaced online, ensuring uninterrupted power supply.
3.Improved Maintenance Efficiency: Modular design reduces maintenance workload by 70%.
4.Optimized Comprehensive Cost: Saves 25% in total investment compared to traditional equipment.
5.Reduced Operating Energy Consumption: Low-loss design saves 30% in annual electricity operating costs.
6.Operational Safety: Comprehensive interlocking and protection functions ensure personnel safety.
7.Equipment Safety: Multiple protections prevent equipment damage.
8.Electrical Safety: Reliable performance guarantees electrical safety.
Product structure
Ⅰ.Overall Frame Design
1. Cabinet Structure:
①Material: High-quality cold-rolled steel plate (thickness ≥ 2.0mm) or aluminum-zinc alloy, surface treated with degreasing, phosphating, and electrostatic spraying, corrosion-resistant and wear-resistant.
②Protection Degree: Standard IP40 (indoor), optional IP54 (dust and water protection), internal compartments independently separated, protection up to IP30.
③Installation Method: Fixed or withdrawable (can be installed front/rear), supports against-wall or away-from-wall placement, saving space.
2. Functional Zoning:
①Busbar Compartment: Top horizontal busbar + vertical busbar, fully insulated protection, supports high current transmission (≤6300A).
②Drawer Unit Compartment: Modular drawers (1E/2E/4E/8E), flexible configuration for feeder, motor control, capacitor compensation, etc.
③Cable Compartment: Large bottom space for wiring, supports top or bottom cable entry, standardized cable clamps.
Ⅱ.Core Component Structure
1.Drawer Unit System
①Guide rail guidance + roller assistance for smooth insertion/extraction; Crank handle operating mechanism for “Connected/Test/Disconnected” position switching.
②Mechanical interlocking device prevents insertion/extraction under load (complies with IEC 60947 standard).
③Main contacts silver-plated, low contact resistance, withstands current impact.
④Secondary plugs use anti-misinsertion design to ensure reliable control
circuit connection.
⑤Horizontal Busbar: TMY copper bar, tin-plated surface, rated current ≤ 6300A, segmented insulated wrapping.
⑥Vertical Busbar: Modular plug-in design, supports future expansion, rated current ≤ 1600A.
2.Safety Protection Structure
①Metal partitions between compartments, directional arc energy pressure relief during faults (top pressure relief channel).
②Independent PE grounding bar, multiple grounding points throughout the cabinet, grounding resistance ≤ 0.1Ω.
Ⅲ.User-Friendly Detail Design
1. Operation and Maintenance Convenience
①Front door design: Double or single door optional, opening angle ≥ 180°, ample maintenance space.
②Visual window: Transparent polycarbonate viewing window for real-time viewing of circuit breaker status/meter data.
③Identification system: Drawer label slots + busbar phase sequence color codes (Yellow/Green/Red), prevents misoperation.
2. Heat Dissipation and Noise Reduction
①Ventilation structure: Top ventilation holes + bottom dust filter screen, forms natural convection air duct (optional forced fan).
②Noise reduction treatment: Busbar clamps use damping material to reduce electromagnetic vibration noise.
Ⅳ.Main Component Structure Description
| Component Name | Material/Specification | Structural Characteristics | Function Description |
|---|---|---|---|
| Cabinet Frame | High-quality CRS (≥2.0mm) | - Integral welding or bolt assembly, high strength | Supports overall structure, protects against external environmental influences |
| - Surface anti-corrosion treatment (galvanizing/spraying) | |||
| Horizontal Busbar | Copper bar (TMY, tin-plated) | - Segmented insulated wrapping | Main circuit power distribution |
| - Rated current ≤ 6300A | |||
| - Top mounted, fully enclosed protection | |||
| Vertical Busbar | Copper bar (TMY, tin-plated) | - Modular plug-in design | Branch circuit power distribution |
| - Rated current ≤ 1600A | |||
| - Direct connection to drawer units | |||
| Drawer Unit | Galvanized steel + Engineering plastic | - Standard modules (1E/2E/4E/8E) | Flexible configuration for feeder, motor control, and other functional circuits |
| - Crank handle mechanism + three-position interlock | |||
| - Main contacts silver-plated | |||
| Circuit Breaker Chamber | Flame-retardant plastic (VO grade) | - Independent compartment design | Installs circuit breakers, isolates arc risk |
| - Ventilation holes + arc chute | |||
| Cable Chamber | Cold-rolled steel plate | - Large bottom space layout | Cable access and fixation |
| - Removable cable clamps | |||
| - Supports top/bottom cable entry | |||
| Metering Compartment | Transparent polycarbonate panel | - Standard mounting rail (35mm) | Installs smart meters, communication modules, etc. |
| - Separate wireways for power/control cables | |||
| Grounding System | Copper bar (TMY) | - Independent PE bar, multiple grounding points | Ensures equipment and personnel safety |
| - Grounding resistance ≤ 0.1Ω | |||
| Pressure Relief Channel | Metal partition + Vent | - Directional pressure relief during fault arcs | Releases internal pressure, prevents cabinet rupture |
| - Top or rear placement | |||
| Interlock Mechanism | Stainless steel mechanical parts | - Drawer three-position lock (Connected/Test/Disconnected) | Ensures operational safety |
| - Prevents operation under load | |||
| Cooling System | Aluminum alloy vent mesh + Optional fan | - Natural convection air duct design | Controls internal temperature rise |
| - Dust filter (IP54 version) |
Specification
Switchgear Technical Parameters
| Item | Technical Parameter |
|---|---|
| Rated Voltage | AC 380V / 660V |
| Rated Insulation Voltage | 1000V |
| Rated Frequency | 50/60Hz |
| Main Busbar Rated Current | 630A~6300A (Note: Corrected range based on Section 2) |
| Vertical Busbar Rated Current | 1600A (Note: Corrected based on Section 2) |
| Rated Short-Time Withstand Current (Icw) | 50kA (1s) |
| Rated Peak Withstand Current (Ipk) | 105kA |
| Protection Degree (IP) | IP30, IP40 |
When using MNS Withdrawable Low-Voltage Switchgear Assembly , you may want to know the following questions & answers.
Ⅰ.Basic Product Questions
1.What are the main application scenarios for MNS withdrawable switchgear?
Suitable for industrial power distribution (e.g., factory MCC motor control centers), commercial buildings (hospitals, data centers), new energy (PV/wind grid connection), and other low-voltage power distribution systems requiring high reliability and modular management.
2.What are the advantages of the "withdrawable" design of MNS cabinets?
Supports quick plug-and-pull maintenance, drawer units can be replaced live (requires professional operation), reducing downtime; Three-position interlock (Connected/Test/Disconnected) ensures operational safety.
3.How to choose between protection degrees IP40 and IP54?
①IP40 is suitable for clean indoor environments
②IP54 is suitable for dusty or humid locations (e.g., outdoor substations, coastal factories), must be specified when ordering.
Ⅱ.Technical Parameters & Configuration
1.What does the module (1E/2E/4E/8E) for drawer units mean?
1E = 25mm (height module), 8E = 200mm. For example: An 8E drawer can install a 630A circuit breaker, a 1E drawer is suitable for ≤32A miniature circuit breakers.
2. Is it compatible with circuit breakers from different brands (e.g., Schneider, ABB)?
Supports mainstream brand circuit breakers, but models must be provided in advance to adapt the drawer mechanical structure and electrical interfaces.
Ⅲ.Installation & Maintenance
1. What are the site requirements for installation?
Requires level ground, ambient temperature -25°C ~ +70°C, humidity ≤ 95%; When multiple cabinets are placed side-by-side, reserve ≥ 50mm heat dissipation gap between cabinets.
2. What to do if the drawer is difficult to insert/extract?
Check if the guide rails are aligned, clear foreign objects; Drawers not operated for a long time need manual shaking and lubrication first. Never force insertion/extraction!
What needs to be done for routine maintenance?
Regularly check busbar connection tightness, remove dust, monitor drawer contact temperature rise (infrared thermometer), professional inspection recommended annually.
Ⅳ.Intelligent Functions & Fault Handling
1. How to achieve remote monitoring?
Optional smart meters (e.g., PM500 series) + communication modules (Modbus/Profibus), connect to SCADA or cloud platform.
2. How to handle an "Overtemperature" device alarm?
Immediately check if the load exceeds capacity, if ventilation is blocked; Long-term overload requires capacity expansion or circuit redistribution.
3.How to reset after a short-circuit fault?
①First disconnect the power supply, locate the fault point
②Resetting the circuit breaker requires the drawer to be in the “Disconnected” position, live operation is strictly prohibited!
Why Choose us ？
Built to last, engineered to perform.
Kete Transformer is a key national-level manufacturer specializing in transformers, recognized as a “Contract-Honoring and Promise-Keeping” enterprise, a high-tech enterprise, and a national-level enterprise technology center. It is recommended in the national directory for rural and urban power grid construction and renovation, as well as a recommended supplier of major electromechanical equipment for hydropower projects. Its products have been awarded the title of “National Quality Inspection Qualified Product – Quality Trustworthy Product” and “Nationally Recognized Product for Mechanical Industry Users.
Our Project
Our products not only dominate the domestic market but are also exported to more than 30 countries and regions, including Russia, Southeast Asia, Africa, and the Americas, serving industries such as power, municipal engineering, metallurgy, and petrochemicals.
