MNS drawer-type switchgear
- Frame: C-profile bolted assembly (modular), frame and drawer unit dimensions unified to the module
- Drawers: 8E / 16E / 24E units, mechanically interlocked in withdrawn, isolated and service positions
- Contacts: silver-plated primary plug-in contacts, insertion and withdrawal force and contact resistance tested on every unit
- Separation: busbar, cable and component compartments segregated so a fault does not spread between zones
- Testing: drawer operation test plus powered functional test on every unit, contact temperature rise under control
Specifications
The table below covers 80% of factory distribution room cases. Anything outside it we can still build — those are engineered items, quoted separately, with an indicative price the same day.
| Type | Drawer-type low-voltage switchgear with modular C-profile bolted frame |
|---|---|
| Standard sizes (W×D×H) | Cabinet width 600 / 800 / 1000 mm, depth 600 / 1000 mm, height 2200 mm, can be banked into rows |
| Frame structure | C-profile (galvanized / aluminum-zinc coated) bolted assembly, modular punching, high strength and reconfigurable |
| Drawer unit | 8E / 16E / 24E units (1E=25 mm), withdrawn, isolated and service positions |
| Primary contacts | Silver-plated plug-in contacts, insertion and withdrawal force and contact resistance tested on every unit |
| Compartmentalization | Busbar, cable and component compartments segregated so a fault does not spread between zones |
| Surface treatment | Electrostatic powder coating 60–80 μm, baked at 200℃ |
| IP rating | IP30 / IP40 standard (drawer compartments need ventilation), IP54 available |
| Rated voltage | AC 380V / 400V, 50 Hz, three-phase |
|---|---|
| Main busbar current-carrying capacity | Horizontal main busbar ≤2000 A (higher currents quoted per project), vertical busbar configured by cabinet type |
| Drawer capacity | Maximum rated current per drawer up to 630 A (determined by drawer size and heat dissipation) |
| Drawer functions | Incoming, feeder, motor control, VFD and soft starter units can all be built as drawers |
| Protection configuration | Circuit breaker + thermal-magnetic / electronic trip unit; motor drawers fitted with contactor and thermal overload relay |
| Position interlock | Drawers cannot be withdrawn while energized; main circuit must be disconnected before withdrawal |
| Grounding systems | PE grounding busbar is separate; drawer grounding contacts make reliable contact with the cabinet frame |
| Component brands | Schneider / ABB / Siemens / Chint |
| Incoming drawer + feeder drawers | Incoming unit combined with multiple feeder drawer units for high circuit density |
|---|---|
| Motor control center | Multiple motor drawer units with contactors and thermal overload relays, local or remote control |
| VFD drawer unit | VFD built as a fixed compartment or drawer unit with a dedicated cooling duct |
| Dual Power Source Incoming Lines | Two incoming drawers + bus tie for dual-source transfer and bus coupling |
| Power factor correction unit | Capacitor compensation built as drawer units with automatic switching based on power factor |
| Cabinet lineup | Multiple cabinets paralleled into a lineup with continuous horizontal busbar for flexible expansion |
| Reference standards | GB/T 7251.1 / IEC 61439-1 (assemblies); GB/T 7251.8 (drawer-type assemblies) |
|---|---|
| Clearance & creepage | Meets pollution degree 3 and overvoltage category III requirements |
| Insulation resistance | ≥1 MΩ (500V megohmmeter) |
| Power frequency withstand voltage | Main circuit 2500V / 1 min, control circuit 1500V / 1 min |
| Drawer operation test | Drawer-by-drawer verification of withdraw, isolated and connected positions plus interlocks |
| Routine tests (every unit) | Insertion/withdrawal force and contact resistance, circuit continuity, dielectric withstand, grounding continuity, energized function test |
| Documents with shipment | Electrical schematic, drawer circuit schedule, BOM with brand and model, test report, factory photos |
Five steps to specify your run
A configuration summary is generated as you go. It travels with your inquiry, saving a round of confirmation.
Build details
Systems have been in service for decades, and the failure points are always the same few: poor busbar contact, water ingress at the door seal, high temperature rise in the correction cabinet, and mis-phased outgoing feeders. The six hard rules below are written for exactly these points — every cabinet can be traced to them.
Silver-plated primary contacts
Primary plug-in contacts are silver-plated; insertion and withdrawal force and contact resistance are tested on every unit. Contacts are the most critical joint in a drawer cabinet — poor contact means heat and arcing.
Draw-out / isolated / connected positions with interlock
Each drawer has three positions — draw-out, isolated and connected — with a mechanical interlock. It cannot be pulled out while energized; that is the safety baseline, do not bypass it.
Separate compartments for busbar, cable and components
Busbar, cable and component compartments are separated. If one circuit faults, arc and heat do not spread across compartments, and maintenance is performed only in the relevant compartment.
C-profile frame
The frame is bolted from C-profile sections with modular punched holes. Rigid enough that drawer rails run smoothly and do not wobble after long-term insertion and withdrawal.
8E / 16E / 24E units
Unit heights are laid out on a 1E = 25 mm module, with flexible combinations of 8E, 16E and 24E. Once the circuit schedule is set, the number of cabinets required is known.
Drawer operation test
Every drawer undergoes insertion/withdrawal operation and powered testing before shipment. Failure to seat fully or interlock failure is caught at the factory.
Photos & enclosure construction
Below are photos taken in our own shop — from the complete unit down to the internal busbars and secondary wiring. Every build detail can be checked item by item.
Image key: 01–05 are shop photos (the numbers match the shot list). The line drawing shows the front elevation of the enclosure; dimensions match the specification table above.
Where these cabinets go
These are the routine applications — we can talk scheme and configuration directly. For the industry view, see the industry pages.
Factories & Substations
Low-voltage distribution with high currents and many circuits, where maintenance must be done frequently without shutting off power.
Motor control center
Drawer-type centralized control for multiple motors — pull the faulty one, leave the rest running.
Data centers and equipment rooms
Distribution systems with high circuit density and a requirement for maintainability.
Large Commercial Buildings
Distribution systems with many circuits and tiered power supply.
Water Plants & Pump Stations
Centralized distribution for pump equipment, with maintenance that does not interrupt water supply.
Industrial Production Lines
Assembled distribution that needs flexible branching and easy expansion.
Commercial terms
Specification dated September 2026; quotations follow this.
| Drawings & design | Free |
| MOQ | 1 unit (5 or more recommended for production) |
| Production lead time | 15-25 days after drawing approval |
| on-time delivery | 98% |
| Warranty | 12 months |
| Loading port | Ningbo / Shanghai, China |
| Component brands | Schneider / ABB / Siemens / Chint |
| Factory visit & dispatch confirmation | Factory visits welcome; finished-cabinet photos and video before dispatch |
| Capacity | 5,800+ units / year |
Documents for your engineering team
Selection manual, outline dimensions and RFQ checklist — for the customer's electrical engineer. All three documents are being organized by product line; download links go live once complete.
Six questions procurement and electrical engineers ask most
MNS or GGD — how do I choose?
It comes down to maintenance needs. GGD is fixed-type: simple construction, lower cost, suited to applications with few circuits and infrequent maintenance. MNS is drawer-type: circuits are built as drawers that can be pulled out for maintenance, suited to applications with many circuits that must be serviced without a power shutdown. Drawer cabinets also carry higher cost and tighter precision requirements.
How many drawers fit in one cabinet?
It depends on the unit height. Taking a 2200 mm cabinet with roughly 72E (about 1800 mm) of usable height per cabinet: 8E units fit 9 in theory, 16E units fit 4, 24E units fit 3, and mixed configurations are laid out by actual combination. We will run through your circuit schedule and tell you how many cabinets you need.
Can a drawer be withdrawn while energized?
No. A mechanical interlock opens the main circuit before the drawer can be withdrawn. Pulling a drawer under load will arc and damage the contacts — that is exactly why the interlock exists, so do not bypass it.
Can the primary contacts develop poor contact?
This is the key component of a drawer cabinet. We use silver-plated contacts, test insertion and withdrawal force and contact resistance on every unit, and run drawer operation tests to confirm all three positions engage correctly. In service, we also recommend scheduled infrared temperature checks per your procedures.
Can VFDs also be built as drawers?
Yes, but VFDs generate significant heat and also require parameter commissioning. Most projects build the VFD units as fixed, compartmented sections with a dedicated air duct, and use drawers for the remaining circuits. The final split is set by your circuit schedule and heat dissipation requirements.
What do I need to provide for an inquiry?
Motor circuit schedule (power, starting method and control requirements for each motor), short-circuit capacity or transformer capacity, incoming and outgoing requirements, and cabinet installation location and size limits. A system diagram is ideal; if you do not have one, a circuit schedule is enough for us to produce a preliminary plan.
Other cabinet types in the same main circuit
Related products use color-block placeholders for now (product photos not yet complete; they will be replaced together). Internal links will be filled in once live URLs are confirmed.
Many circuits and no downtime allowed? Use drawers to drive down maintenance cost
Send us your motor circuit schedule and transformer capacity, and we will lay out the cabinet types and drawer configuration free of charge · quotation within 24 hours. Direct from the source factory, MOQ 1 unit, 15–25 day delivery, 1-year warranty.
ISO 9001:2015 · CE(LVD+EMC) · CQC · IP65
When you write, include: single-line diagram or primary scheme, switch room layout, load list, and component brand requirements. You do not need complete drawings — capacity and cabinet type are enough to start.