Description
Our low voltage distribution boards take power from the transformer and distribute it safely to motors, lighting, HVAC and process loads. Each board is configured from your single-line diagram and load list, then built and routine-tested in our Hangzhou factory.
Low-Voltage Switchgear Cabinet Overview
A low voltage distribution board brings together the main incoming breaker, busbars, outgoing feeder breakers, metering, protection and often motor control in one enclosed assembly rated up to 1,000 V AC. It protects cables and equipment from overload and short circuit, isolates circuits for maintenance and provides the data operators need to manage energy use.
Cabinet Types We Build
| Type | Construction | Typical use |
|---|---|---|
| Power distribution centre (PCC) | Fixed or withdrawable ACB incomers and feeders | Main board directly after the transformer |
| Motor control centre (MCC) | Withdrawable or plug-in starter units, soft starters and VFDs | Groups of pumps, fans, conveyors and process motors |
| GCS / MNS withdrawable type | Drawer-type functional units, high reliability | Industrial plants and critical facilities |
| GGD fixed type | Fixed components, simple and economical | Buildings and general industrial distribution |
| Capacitor / SVG cabinets | Power-factor correction and harmonic filtering | Plants with many motors or drives |
Key Features
- Coordinated protection – ACBs, MCCBs and fuses selected and set for selectivity, so only the faulty circuit trips.
- Robust busbar system – copper busbars sized for rated and short-circuit current.
- Internal separation – forms of separation up to Form 4 for safe work on one circuit while others stay live.
- Metering and monitoring – multifunction meters with Modbus or Ethernet for energy management and SCADA.
- Automatic transfer – ATS or interlocked breakers for generator back-up of essential loads.
- Flexible enclosures – front or rear access, top or bottom cable entry, IP31 to IP54 and higher on request.
Typical Ratings
- Rated voltage up to 690 V AC (IEC low voltage range up to 1,000 V)
- Main busbar current from a few hundred amperes up to about 6300 A depending on design
- Short-circuit withstand matched to the transformer and supply fault level
- Forms of separation 1 to 4
Exact ratings are confirmed for each project against your single-line diagram and fault study.
Applications
Factory and process plant distribution, motor control for pumps, fans and conveyors, commercial and public buildings, data centres and hospitals, water and wastewater plants, and power distribution in mining, metals and oil and gas facilities. Read what low voltage switchgear is and how it compares with medium and high voltage switchgear.
Standards and Testing
Assemblies are designed and verified to IEC 61439-1 and IEC 61439-2. Every board receives routine verification before delivery, including inspection of wiring and clearances, dielectric tests, insulation resistance and functional tests of control circuits and interlocks. Drawings, settings lists and test reports are supplied with the equipment.
Installation and Maintenance
Boards are shipped in transport sections with busbar links and installation instructions. The room should provide front (and rear, if required) access clearances, a level base, cable trenches or trays, and ventilation for heat-producing equipment such as VFDs. Annual maintenance — thermographic scans under load, terminal torque checks, cleaning and breaker exercise — keeps the board reliable. Our after-sales team supplies spare breakers, drawers and parts.
What to Send for a Quotation
- Single-line diagram and load or motor list
- Transformer rating and prospective short-circuit current
- Preferred breaker and drive brands
- Form of separation, IP rating and cable entry
- Metering, communication and any transfer scheme required
See also our VFD cabinets and high-voltage switchgear, or request a quote.
Common Specification Mistakes to Avoid
- Rating the board for normal current only and forgetting the short-circuit withstand at the installation point.
- Leaving no spare feeders or space, so later additions need a new board.
- Ignoring heat from drives and electronics, which leads to derating or nuisance trips in hot climates.
- Using fixed units for critical motors where withdrawable units would cut repair time from hours to minutes.
- Not coordinating breaker settings, so a fault on one circuit trips the main incomer and stops the whole plant.
Why Choose Danli
We design the low voltage board together with the transformer, medium voltage switchgear and automation system around it, so ratings, protection and communication are coordinated across the whole installation. Boards are built and tested in our own factory with components from the brands you specify, documentation is supplied in English for export projects, and our engineers support installation, commissioning and long-term maintenance. Typical lead times are confirmed in every quotation, and we keep you updated from drawing approval to shipment.
Example Configuration
A 1600 kVA transformer feeding a process plant might supply a main board with a 2500 A ACB incomer, a bus section with essential loads backed by a generator through an automatic transfer scheme, outgoing MCCB feeders for HVAC, lighting and workshops, and a withdrawable motor control section with soft starters and VFDs for pumps and fans. Multifunction meters on the incomer and major feeders report energy and power quality to the plant SCADA.
Frequently Asked Questions
What voltage do your low voltage panels support?
Typical systems are 400/230 V, 480 V and 690 V AC at 50 or 60 Hz, within the IEC low voltage range of up to 1,000 V AC.
What is the difference between fixed and withdrawable designs?
In fixed designs the components are permanently mounted, which is simpler and cheaper. In withdrawable designs such as GCS or MNS, functional units are on drawers that can be replaced quickly without shutting down the whole board.
Which breaker brands do you use?
We use ACBs, MCCBs and contactors from leading international and Chinese brands, according to your specification.
Can the board include motor starters and VFDs?
Yes. Boards can combine power distribution feeders with motor control units, soft starters and VFDs in a motor control centre arrangement.
