EN
4M‑Half Blokset Drawer Module - Half Width, 400 mm High, up to 160A
4M/2 half-width Blokset drawer module, 400mm height, up to 160A. Weld-free 8MF frame system, 73.5kA peak, three-position isolation. Kits for local assembly.
- Overview
- Applications
- Technical Data
- Services
- Quality Control
- Recommended Products
4M‑Half Blokset Drawer Module - Half Width, 400 mm High, up to 160A
4M/2 is the density module of the M-Blokset system. It is 400 mm high and half a compartment wide, so two modules sit side by side in the space one full-width module would occupy. On a motor control centre with a long list of small and medium feeders, this is the module that decides whether the lineup is six sections or eight.
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.
WHERE THE COMMERCIAL ADVANTAGE IS
Two sections saved on a lineup is two frames, two sets of doors, the busbar length between them, the cabling, the floor area and the freight. On a tender where every bidder is offering broadly the same components, section count is one of the few places a panel builder can legitimately take cost out without cutting quality. Quote the half-width module wherever the feeder rating allows it.
WHAT YOU ARE BUYING WHEN YOU BUY THE MODULE
The mechanism, already right. Isolating contact alignment, contact pressure, three-position latch geometry, secondary plug engagement and earth contact sequencing are precision work; they look fine on a workshop bench and fail eighteen months later under thermal cycling. Each module is delivered assembled, wired, labelled and individually tested with its own routine test certificate, so what your team assembles is a cabinet, not a mechanism.
SUPPLIED READY OR AS A KIT
Built to your feeder schedule with your specified device brand. Or as a CKD kit - shell, isolating contacts, racking mechanism, interlock, handle, secondary plug and pre-cut modular harness - with the assembly drawing, torque figures and gauge sheet. The pre-cut harness removes about 30% of assembly labour compared with cutting and crimping wire by wire.
PRIMARY APPLICATIONS
- Small and medium motor starters in M-Blokset motor control centres, up to approximately 45 kW.
- Distribution feeders up to 160A in Blokset-platform boards.
- High feeder-count motor control centres where section count must be minimised.
- Water treatment, sewage and pumping plants with many valve, dosing and small pump circuits.
- Food, beverage, packaging and pharmaceutical lines with many small drives.
- Building services: air handling units, pump sets, small chiller auxiliaries.
- Retrofit projects where the existing switchroom width is fixed.
- Cement, mining and steel plant auxiliary drive sections.
TYPICAL CONFIGURATIONS
Direct-on-line starter with contactor, overload relay and control circuit; star-delta starter; reversing starter; distribution feeder with MCCB; feeder with electronic motor protection relay and fieldbus communication.
WHY THE MODULE SIZE IS CHOSEN
Because the feeder does not need a full-width compartment and the switchroom does not have spare width. It is a straightforward density decision, made at design stage when the feeder schedule is first laid out against available floor space.
REGIONAL FIT
- Middle East: high feeder counts in desalination, district cooling, building services and process plants. Switchroom ambient of 50-55 C requires derating above the IEC +40 C reference. SASO SABER, DEWA, KAHRAMAA, MEW and Oman DCRP documentation supported.
- Africa: water, agro-processing, mining auxiliaries and industrial plants. Weld-free local assembly is particularly valuable here, since it removes the freight on cabinet volume and shortens delivery to remote sites.
- Russia and CIS: 380V/220V, EAC under TR CU 004/2011 and TR CU 020/2011.
- Eastern Europe: 400V, CE under LVD 2014/35/EU and EMC 2014/30/EU to EN 61439-2.
NOT SUITABLE FOR
Feeders above the module rating - step up to 3M or 6M. MOLDVOLT-platform cabinets, which use the 1/2, 1, 1.5 and 2 unit drawer range instead. Fixed-type boards such as GGD, XL-21 and JXF.
TECHNICAL DATA - 4M/2 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 160 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 | 4M/2 (400 mm height, half width) |
| Module width | half compartment width - two modules side by side | |
| Module height | 400 mm (1M = 100 mm) | |
| Modules per standard section | up to 20 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 160 A, or contactor-based starter up to approximately 45 kW |
| Feeder types | distribution feeder, direct-on-line starter, star-delta starter, reversing starter | |
| Motor protection | thermal overload relay, or electronic motor protection relay with earth fault and 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
Two 4M/2 modules occupy the width of one full-width compartment, giving the highest feeder density on the Blokset platform. Use it to reduce section count on high feeder-count lineups and on retrofits where switchroom width is fixed.
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.
