The Heart of Your Low-Voltage Distribution
A main low-voltage switchboard is the central point at which incoming power is received, protected and distributed to downstream loads. It carries the highest currents in a typical installation, so it must be engineered for fault withstand, thermal performance and operator safety. A weakness here propagates through the whole installation, which is why the main switchboard deserves the most careful engineering.
Exa Power builds main and sub-main LV switchboards on authorized ABB systems such as ArTu and ArTuMax, with every assembly designed and verified to IEC 61439. Configurations range from compact distribution boards to large multi-section switchboards with high short-circuit ratings, single or multiple incomers, bus-couplers and extensive outgoing feeders.
Because we build within ABB’s type-tested system, the thermal and short-circuit behaviour of each configuration is characterised in advance. That means the ratings we quote are backed by the system design rather than estimated, and the assembly behaves predictably under both normal load and fault conditions.
What Our Switchboards Offer
High Fault Withstand
Flexible Configurations
Metering & Monitoring
Operator Safety
Form Separation
IEC 61439 Verified
Product categories we supply
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Engineered for Fault and Heat
Two performance criteria dominate switchboard design: the ability to withstand short-circuit currents without damage, and the ability to carry continuous load without overheating. We size the busbar system, select breakers and arrange the internal layout so that both are satisfied within the limits established by the ABB type-tested system. Prospective short-circuit current, peak withstand and short-time withstand ratings are matched to the fault data you provide.
Temperature rise is treated with equal care. The continuous current the busbar and devices can carry depends on enclosure size, ventilation, ambient temperature and how loads are grouped. By working within the verified design and accounting for the actual ambient and load conditions on site, we avoid the hidden derating that causes nuisance tripping and premature ageing in poorly engineered boards.
The result is a switchboard whose nameplate ratings mean what they say: it carries its rated current continuously in the real environment, and it survives the prospective fault without endangering operators or the rest of the installation.
What We Can Incorporate
Air circuit breakers (ACBs) and moulded-case circuit breakers (MCCBs) on ABB ranges.
Busbar systems rated for the required continuous and fault current.
Incomer, bus-coupler and outgoing feeder arrangements.
Internal separation to the required form, from Form 1 to Form 4.
Metering, protection relays and monitoring devices.
Power-quality instruments and communications gateways where required.
Cable or busduct entry from top or bottom, with planned termination space.
Where it is used
Where it is used
Choosing the Right Form of Separation
Internal separation balances safety, maintainability and cost.
Form 2
Form 3
Form 4
Specified to Project
How We Engineer a Switchboard
The engineering of a main switchboard begins with the electrical duty and the environment it must work in. From your single-line diagram we establish the incomer and feeder arrangement, the metering and protection scheme and the bus-coupling philosophy. From the fault data we select breakers and size the busbar system for the prospective short-circuit. From the site ambient and the load grouping we confirm the continuous current the board can carry without exceeding its temperature-rise limits. None of these is treated in isolation, because they interact: a higher ambient, for example, may call for a larger busbar or more generous enclosure to hold the same rating.
We then resolve the physical design: section sizes, the form of separation, cable or busduct entry, and the access required for safe operation and maintenance. The output is a coordinated set of drawings and a bill of materials that, once approved, drives both the build and the as-built records. Because the design sits within the ABB type-tested system, each of these choices is made within rules whose performance has already been verified, which is what keeps the finished switchboard both compliant and predictable.
The Busbar System at the Core
The busbar system is the spine of a switchboard, distributing current from the incomer to every outgoing feeder. Its cross-section, bracing and support are engineered to carry the rated continuous current without excessive temperature rise and to survive the prospective short-circuit without distortion or damage. Within the ABB type-tested system the busbar arrangement, the spacing and the bracing are defined, so the assembly’s withstand performance is a property of a verified design rather than an estimate made on the workshop floor.
Around the busbars, the construction is arranged for safe access and clean cable management. Incomer and feeder compartments, the chosen form of separation, and generous, planned termination space all make the board safer to work on and easier to maintain. We plan cable or busduct entry, top or bottom, around the actual cables specified for the site, so installation on site is straightforward and the terminations are accessible for inspection.
From Single-Line to Switchboard
To specify a switchboard, share your single-line diagram, fault levels, feeder schedule and any metering or monitoring requirements, along with the site ambient temperature and the required form of separation. Our engineering team will translate this into a compliant ABB-based design and return a technical proposal with quotation, including the recommended form of separation, the busbar rating and an indicative lead time.
Every switchboard is factory tested before dispatch, and where the project requires it we can arrange witnessed factory acceptance testing so your team confirms performance before release. Design and routine-test documentation, as-built drawings and O&M guidance are issued with the assembly and remain available on request, giving you the records to support commissioning, operation and any future modification.
Frequently asked questions
Frequently asked questions
Specify Your Main Switchboard
Send your single-line diagram and fault data and we will engineer a compliant ABB-based switchboard for your project.
Request a Quote