EN
3M Blokset Drawer Module - Full Width, 300 mm High, up to 250A
3M full-width Blokset drawer module, 300mm high, to 250A. Weld-free 8MF frame, 73.5kA peak, three-position isolation, individually tested.
- Overview
- Applications
- Technical Data
- Services
- Quality Control
- Recommended Products
3M Blokset Drawer Module - Full Width, 300 mm High, up to 250A
3M is the reference module of the M-Blokset system - full compartment width, 300 mm high, and sized for the majority of motor starters and distribution feeders on a real project. If you are building a Blokset motor control centre, this is the module you will make in the largest quantity, and it is the size everything else is measured against.
THE M-BLOKSET PLATFORM
These modules belong to the M-Blokset system, which is a different mechanical platform from the MOLDVOLT drawer range. It is built on an 8MF cold-bent, weld-free frame - the frame is formed and bolted rather than welded, which keeps it dimensionally accurate, lets it be shipped flat and assembled locally, and removes the welding distortion that throws drawer alignment out on a welded structure. Busbars are supported by ZM clamps moulded in flame-retardant PPO, giving 73.5 kA peak withstand, and the system carries up to 2500A with IP20 to IP54 protection and top-mounted pressure relief.
WHY WELD-FREE MATTERS TO YOU
A weld-free frame is the single feature that makes local assembly realistic. A welded frame has to be built in a factory with jigs and then shipped as a finished volume. A bolted frame ships flat, is assembled with hand tools against a drawing, and comes out square every time. That is what converts an imported cabinet into a locally built one - and it is where the freight saving lives, since a cabinet is mostly air.
MODULE NOTATION
Module height is expressed in M units, where 1M equals 100 mm of compartment height. A 3M module is 300 mm high and full width; a 4M/2 module is 400 mm high and half width, so two sit side by side in one compartment; a 6M module is 600 mm high and full width.
WHAT THE CLIENT IS ACTUALLY BUYING
Uptime. On a continuous process line, a failed motor starter stops production, and the cost of that stoppage per hour usually exceeds the entire price difference between a fixed board and a withdrawable one. With a withdrawable module, an electrician racks the failed unit out and a tested spare in, and the line runs again in minutes. That is the argument to make when a client questions the price of a withdrawable board - not the technical specification, the hourly cost of a stopped line.
WHERE LOCALLY BUILT DRAWERS GO WRONG
Panel builders who fabricate their own modules generally get the shell right and the mechanism wrong. Contact alignment and contact pressure decide whether the joint runs cool for fifteen years or slowly cooks; three-position latch geometry decides whether Test is genuinely Test; earth contact sequencing decides whether the unit is safe during racking. None of it is visible after handover. Each module we supply is assembled, wired, labelled and individually tested, and arrives with its own routine test certificate.
INTERCHANGEABLE, YEAR AFTER YEAR
Module dimensions are held to the same drawing revision over time, so a replacement 3M supplied in year five fits a board built in year one. An in-house module design cannot promise that, which is precisely why consultants write standardised systems into specifications.
SUPPLIED READY OR AS A KIT
Built to your feeder schedule with your specified device brand, or as a CKD kit with shell, isolating contacts, racking mechanism, interlock, handle, secondary plug, pre-cut modular harness, assembly drawing and torque sheet.
PRIMARY APPLICATIONS
- Standard motor starters in M-Blokset motor control centres, up to approximately 90 kW.
- Distribution feeders up to 250A in Blokset-platform boards.
- Soft starter feeders within the module envelope.
- Pump, fan, conveyor, compressor, mixer and agitator drives.
- Cement, steel, mining, sugar, paper, textile and food processing plant MCCs.
- Water treatment, sewage and desalination plant motor control.
- Building services: chiller plant, air handling, pump sets, car park ventilation.
- Petrochemical and oil and gas utility motor control.
- Port, terminal and materials handling drive sections.
TYPICAL CONFIGURATIONS
Direct-on-line starter; star-delta starter; reversing starter; soft starter with bypass where the envelope allows; distribution feeder with MCCB and metering; feeder with electronic motor protection relay and fieldbus communication.
WHY BUYERS SPECIFY IT
Because it covers most of the feeder schedule with one module size, which simplifies spares, training and stock. A plant holding two or three spare 3M modules covers the majority of its motor feeders.
REGIONAL FIT
- Middle East: heavy MCC demand across desalination, district cooling, petrochemical, cement and building services. Switchroom ambient of 50-55 C requires derating above the IEC +40 C reference. Witnessed factory acceptance testing is standard on Saudi SEC and comparable utility projects.
- Africa: mining, cement, water and agro-processing. Remote sites make on-site spare modules an operational necessity, and weld-free local assembly cuts both freight and lead time.
- Russia and CIS: 380V/220V, EAC under TR CU 004/2011 and TR CU 020/2011.
- Eastern Europe: 400V, CE under LVD and EMC to EN 61439-2, often with fieldbus motor management specified.
NOT SUITABLE FOR
Feeders above the module rating or variable frequency drives needing more ventilation - step up to 6M. MOLDVOLT-platform cabinets, which use the 1/2, 1, 1.5 and 2 unit drawer range. Fixed-type boards such as GGD, XL-21 and JXF.
TECHNICAL DATA - 3M Blokset Drawer Module
Compliance: IEC 61439-1, IEC 61439-2, IEC 60947-2, GB 7251.1
| Category | Item | Parameter Details |
| ELECTRICAL RATINGS | Rated operational voltage (Ue) | 400 V / 415 V AC (380 V available) |
| Rated insulation voltage (Ui) | 1000 V | |
| Rated impulse withstand voltage (Uimp) | 8 kV | |
| Rated frequency | 50 Hz / 60 Hz | |
| Rated current of module | up to 250 A | |
| System rated current (M-Blokset busbar) | up to 2500 A | |
| System rated peak withstand current (Ipk) | 73.5 kA | |
| Rated short-time withstand of the assembly (Icw) | up to 65 kA for 1 s | |
| Control voltage | 230 V AC, 110 V AC, 24 V DC | |
| MODULE GEOMETRY | Module designation | 3M (300 mm height, full width) |
| Module width | full compartment width | |
| Module height | 300 mm (1M = 100 mm) | |
| Modules per standard section | up to 6 modules of this size in a standard section, arrangement dependent | |
| Interchangeability | dimensionally identical across production batches and years | |
| M-BLOKSET SYSTEM CONSTRUCTION | Frame | 8MF cold-bent, weld-free, bolted assembly - ships flat, assembles square |
| Busbar support | ZM clamps moulded in flame-retardant PPO | |
| Busbar | electrolytic copper, silver-plated bolted joints | |
| Pressure relief | top-mounted | |
| Protection degree | IP20 to IP54 depending on configuration | |
| Internal separation | Form 3b / Form 4b per IEC 61439-2 | |
| ISOLATING SYSTEM | Working Positions | Connect / Test / Disconnect, each positively latched with indication |
| Primary contacts | silver-plated copper, spring-loaded, self-aligning | |
| Secondary contacts | silver-plated multi-pin plug, engages in Test position | |
| Earth contact | engages before and breaks after the power contacts | |
| Mechanical endurance | 100,000 operating cycles | |
| Racking mode | manual handle racking with position indicator | |
| INTERLOCKS | Interlock Functions | 1. Module cannot be racked while the device is closed 2. Device cannot be closed between defined positions 3. Door interlocked with device position, defeatable by tool for authorised access 4. Padlocking provision in the Disconnect position |
| FEEDER DEVICE | Applicable MCCB / Starter | MCCB frame up to 250 A, or starter up to approximately 90 kW |
| Feeder types | direct-on-line starter, star-delta starter, reversing starter, soft starter within the module envelope, distribution feeder | |
| Motor protection | electronic motor protection relay with earth fault, thermistor input and fieldbus communication | |
| WIRING | Wiring | pre-cut modular harness, ferruled and labelled, reducing on-site assembly labour by approximately 30% versus wire-by-wire termination |
| Terminals | front accessible, sized for the feeder cable range | |
| TESTING - EVERY MODULE | Factory Test Items | Dielectric withstand 1 minute at rated test voltage; insulation resistance recorded; three-position operation and interlock function verified; contact alignment and engagement gauged; functional test of the feeder logic |
| SERVICE CONDITIONS | Ambient temperature | -5 ℃ to +40 ℃ per IEC; verified to +55 ℃ with derating |
| Relative humidity | 50% at +40 ℃, up to 90% at +20 ℃ | |
| Altitude | up to 2000 m |
OPTIONS
Spare module for hot standby | electronic motor protection relay with Modbus,
Profibus or Profinet | earth fault protection | metering | thermistor input |
60 Hz verification for Saudi Arabia | tropicalised coating | IP54 configuration |
CKD module kit for local assembly
NOTE
This is the reference module size on the Blokset platform. Standardising the bulk of a feeder schedule on 3M simplifies the client's spares holding and your own production, because one module type covers most feeders.
SUPPLIED READY TO INSTALL - THE HARD PART IS ALREADY DONE
A drawer is not a box with a breaker in it. Contact alignment, three-position interlock geometry and secondary plug engagement are the parts of a withdrawable board that local workshops get wrong, and a misaligned drawer is what turns into a burned contact two years later. We supply the units assembled, wired and tested, so your workshop is building a cabinet - not debugging a mechanism.
1. FUNCTIONAL UNITS BUILT TO YOUR SCHEDULE
Send us the feeder schedule and we build the drawers to it: distribution, direct-on-line, star-delta, soft starter, VFD, reversing. Device brand to your specification. Each unit is delivered wired to terminals, labelled and individually tested.
2. INTERCHANGEABILITY GUARANTEED ACROSS BATCHES
Standard module dimensions are held to the same drawing revision year after year. A 1-unit drawer ordered today fits a cabinet you built three years ago. This is the single reason consultants specify a standardised system, and it is where a proprietary in-house drawer design costs the client later.
3. CKD DRAWER KITS FOR LOCAL ASSEMBLY
If you would rather assemble in-house, we supply the drawer as a kit: shell, isolating contacts, racking mechanism, interlock, handle, secondary plug and wiring harness, with the assembly drawing and a torque and gauge sheet. The pre-cut modular wiring harness alone removes about 30% of on-site assembly labour compared with cutting and crimping wire by wire.
4. TRAINING ON THE MECHANISM
Alignment, contact pressure check, three-position verification, interlock function test and racking force check - taught on your own bench with your own units, on site or by video session.
5. SPARE DRAWERS AND SPARES STRATEGY
Quote the spare drawer set with the main order. A hot spare drawer is what lets a plant restore a feeder in minutes instead of hours, and on EPC projects it is often the reason a withdrawable board was specified in the first place. We keep the design available so spares remain buyable for the life of the installation.
6. DOCUMENTATION FOR YOUR SUBMITTAL
Routine test certificate per unit, device certificates, wiring diagram, drawer schedule and part list. Formatted so it drops straight into your IEC 61439 verification file.
7. AFTER-SALES
24-hour technical response, 12 months from commissioning or 18 months from shipment, spare contact and interlock parts held to the same revision.
8. COMMERCIAL TERMS
FOB, CFR, CIF, DDP, Ex-Works. Mixed loading with cabinets and components. Trade Assurance, T/T, L/C. Sample units accepted before volume.
QUALITY CONTROL - EVERY DRAWER TESTED AS A UNIT
A withdrawable board fails at the interface, not in the middle of a component. Contact pressure, alignment and interlock geometry decide whether the drawer is still healthy after a thousand operations, and none of that is visible after the door is closed. Each unit is therefore tested as a complete assembly before it leaves the line.
DIMENSIONAL AND MECHANICAL CHECKS - 100%
1. Shell dimensions and squareness against the module drawing, so interchangeability with earlier batches is real and not assumed.
2. Isolating contact alignment and engagement depth verified with a gauge; contact pressure measured against specification.
3. Silver plating thickness on primary and secondary contacts checked on batch samples.
4. Three-position operation - Connect, Test, Disconnect - each position confirmed to latch positively with correct indication.
5. Interlock function - the drawer cannot be racked with the device closed, and the device cannot be closed between defined positions. Tested in both directions.
6. Racking operating force measured and recorded; a stiff mechanism is rejected, not adjusted at the customer's site.
7. Earth contact sequence verified - the earth contact must make before and break after the power contacts.
8. Mechanical endurance qualified to 100,000 cycles on type-test samples.
ELECTRICAL CHECKS - 100%
9. Wiring verified against the unit schematic; ferrules, terminal tightness and labelling checked.
10. Secondary plug pin-out verified circuit by circuit.
11. Dielectric withstand test at the rated test voltage for one minute, and insulation resistance measured and recorded.
12. Functional test of the feeder logic - starter sequence, protection relay settings, indication and, where fitted, communication.
WHAT YOU RECEIVE
Individual routine test certificate carrying the unit serial number, drawer schedule, wiring diagram, device certificates, and the type-test evidence for the drawer system to support your IEC 61439 verification file.
TRACEABILITY AND SPARES
Every unit is serialised against its drawing revision. When you order a replacement in five years, the drawer that arrives is the drawer that fits. Sample units are supplied for fit-up trials before volume production, and third-party inspection is accepted on request.
