Home > BLOKSET Withdrawable Low Voltage Switchgear （400/690V, Up to 6300A）
Product Description:
STELLAR low voltage switchgear is a type-tested withdrawable assembly for 400V and 690V power distribution, with rated currents up to 6300A and a 100kA/3s short-time withstand. The structure is fully modular — vertical busbar arrangement for natural heat dissipation, dual-clamp drawer contacts, and a standard-thickness busbar system — built and verified to IEC 61439-2.The assembly is used as the main and sub-distribution board in utility networks, data centers, rail transit, hospitals and commercial complexes. Withdrawable drawer units in 2M, 4M/2, 3M, 4M, 6M, 8M, 9M and 12M sizes allow flexible feeder configuration in a single panel, with hot-swap maintenance that does not de-energise adjacent circuits.
Available Configurations
• Rated voltage 400V or 690V, insulation voltage 1000V
• Rated current up to 6300A
• Frequency 50Hz / 60Hz
• Short-time withstand 100kA / 3s
• Internal arc test 100kA / 3s
• Withdrawable drawer sizes 2M, 4M/2, 3M, 4M, 6M, 8M, 9M, 12M
• Protection IP30 to IP54
• Indoor metal-enclosed, single-front or double-front access
• Form 4b internal separation standard, Form 3b and 2b on request
Ordering Information
Send us your single-line diagram with feeder list, incoming arrangement (top or bottom cable entry), short-circuit level at the busbar, ambient conditions and required IP rating. Our engineering team will return a panel layout and front-view drawing for your approval before production.
| Basic Parameters | ||
| Rated Voltage | V | 400/690 |
| Rated Insulation Voltage | V | 1000 |
| Rated Current | Up to 6300A | |
| Frequency | Hz | 50 / 60 |
| Rated Impulse Withstand Voltage | kV | 12 |
| Rated Short-time Withstand Current | kA | 100 |
| Seismic Rating | Level 9 | |
| Salt Spray Test | h | 200 |
| Internal Arc Test | 100kA / 3s | |
| Altitude | m | 4000 |
| EMC Test Report | Available | |
| Drawer Module | 2M, 4M/2, 3M, 4M, 6M, 8M, 9M, 12M | |
| Degree of Protection | IP30-IP54 |
STELLAR low voltage switchgear is designed, manufactured and type-tested to IEC 61439-2 (low voltage switchgear and controlgear assemblies — power switchgear and controlgear assemblies) and the Chinese national standard GB/T 7251.2-2023. Every base configuration has been verified at our in-house test center for temperature rise, dielectric strength, short-circuit withstand, internal arc behavior and EMC performance. Full type test reports are available on request before order placement.
The cabinet is built on a flexible modular framework, with depth options of 400mm, 600mm and 800mm. The cable compartment can be configured 200mm, 400mm or 600mm wide on either side. Internal compartments follow Form 4b separation as standard, with Form 3b and Form 2b available on request. The frame is assembled from C-section steel pillars with bolt-and-rivet joints — no welding inside the load-bearing path — so the structure stays dimensionally accurate after transport and on-site handling.
Functional units sit in fully withdrawable drawers in 2M, 4M/2, 3M, 4M, 6M, 8M, 9M and 12M sizes. Each drawer has three positioned states — Connected, Test, Isolated — with mechanical interlock against operation in intermediate positions. Drawers are hot-swappable: a faulty feeder can be drawn out and replaced without de-energising the main busbar or adjacent circuits, so plant downtime is limited to the affected feeder during maintenance or fault repair.
The horizontal main busbar runs at the top of the panel and is rated up to 6300A. Vertical distribution busbars are arranged in an edge-on (vertical) layout for natural convection cooling, supported by glass-fiber-reinforced polyester busbar holders. Comb-shaped busbar clamps grip the bars at a fixed pitch — this controls the short-circuit force path during a fault and keeps the bars in position after repeated through-faults. Standard-thickness copper busbar dimensions are tested across the full current range, not interpolated from a smaller reference rating.
The high-current bus joint uses a fast-connect copper bar design that allows the 6300A horizontal busbar to be coupled between sections with minimal site bolting, cutting installation time on large multi-panel line-ups. Drawer primary contacts use a dual-clamp head — two independent spring-loaded contact fingers per pole — giving stable contact resistance after thousands of insertion cycles and reducing local heating at the contact zone under high load.
Low voltage switchgear is a metal-enclosed assembly that distributes electrical power below 1000V. STELLAR units are used as main and sub-distribution boards in data centers, hospitals, rail transit substations, industrial plants and commercial buildings, handling both power feeders and motor control circuits in a single cabinet line-up.
Our low voltage switchgear is designed and type-tested to IEC 61439-2 and GB/T 7251.2-2023. Each base configuration has been verified at our in-house test center for temperature rise, dielectric withstand, short-circuit withstand at 100kA/3s and internal arc performance. Type test reports are available on request before order placement.
Standard rated current goes up to 6300A on the horizontal main busbar, with vertical distribution busbars sized according to feeder layout. If your project needs a higher rating or a specific busbar geometry for top or bottom cable entry, send us your single-line diagram and we will confirm the achievable specification in writing.
Each functional unit sits in a withdrawable drawer with three positions — Connected, Test, Isolated. A faulty feeder can be drawn out and replaced while the main busbar and adjacent feeders stay energised, so downtime during a feeder fault or scheduled maintenance is limited to the affected circuit. Drawer sizes 2M through 12M cover feeder ratings from small motor starters up to large incomers.
Yes. Drawer combination, busbar rating, cable entry direction, form of internal separation and IP rating are all configured against your project specification. Send us the single-line diagram with feeder list, short-circuit level and ambient conditions, and our engineering team will return a panel layout and front-view drawing for your approval before production starts.
Form of internal separation defines how barriers are placed between busbars, functional units and cable terminations. Form 2b separates busbars from functional units. Form 3b separates busbars, functional units and terminals from each other but keeps terminals of the same circuit together. Form 4b further separates each circuit's terminals from those of other circuits. We supply Form 4b as standard, with Form 3b and Form 2b on request.
