Main switchboards are the heart of electrical supply to buildings and infrastructure, so it’s critical to specify one that’s fit-for-purpose, Standards compliant, and tested to perform.
Main switchboards are commonly found in large buildings, industrial facilities, and commercial establishments where there is a substantial electrical load. They play a critical role in controlling and distributing electrical power while ensuring the safety of the building’s occupants and the electrical system itself.
Clean Tech Controls assembles and tests Standards-compliant switchboards and associated technology in Australia, with particular expertise in embedded generation, such as renewable energy and diesel generators, including complex installations that connect to the grid.
Modular switchboards are those that are tested by a third party. The switchboard manufacturer bolts the many enclosure components together following the instructions of the supplier. The IP rating* for these switchboards is often around IP42 and suitable only for indoor use.
*IP stands for Ingress Protection, and the first number indicates protection level from ingress of dust and solid materials, while the second number indicates protection from water and other liquids.
“Modular switchboards are good for indoor use, but they have a low IP rating, so they normally can’t be used outside unless a special enclosure is built over the top, which can be expensive. For outdoor applications this often means you need to manufacture two separate enclosures,” explains Steve.
“In contrast, custom enclosure switchboards of the type Clean Tech Controls supplies Australia-wide, are IP56 rated, and can be used outdoors, including on solar farms, rooftop installations, commercial buildings, farms and agricultural installations, EV chargers, carparks, and in building upgrades where the internal switch rooms have no space for new switchboards,” he says.
Custom switchboards are where the enclosure is built for the application. It can be constructed from steel, aluminium, or stainless steel and is normally of welded construction, allowing it to reach much higher IP ratings and makes it suitable for outdoor use. To be able to supply switchboards such as this to the market, the manufacturer must carry out temperature rise testing, short circuit testing, and other tests to verify the design to AS/NZS 61439, which Clean Tech Controls has completed. These tests often cost between $100-200k, depending on the design.
“For outdoor switchboards, a minimum of IP55 is recommended, which means it can withstand multiple jets of water, as well as being protected against dust and debris. If it is in an area susceptible to corrosion, aluminium or stainless steel should be considered,” says Steve.
Knowledge of SIRs
Service and Installation Rules (SIRs) vary in each State and Territory of Australia, and getting these right is imperative to Standards-compliant switchboard design, says Steve.“These rules relate to electrical installation, metering, current transformer chambers, and connection points, for example. Having worked across all States and Territories in Australia, we’ve seen how much these can vary. There’s no ‘one switchboard fits all’ approach that can be taken – it requires in-depth understanding of local rules,” he says.
Safety considerations
In addition to building AS/NZS 61439 compliant switchboards, Clean Tech Controls also emphasises the importance of engineering services such as discrimination studies and arc flash studies to optimise the safety of each installation.
“Discrimination studies are completed when connecting to the grid or upgrading switchboards, and it investigates the circuit breaker curves to see if they will trip to isolate a fault without tripping off more circuits than necessary,” explains Steve.
“Arc flash studies calculate the energy released if an arc fault occurs. Knowing the energy released allowed the owner to determine the PPE required by personnel when working on or around the switchboard. When an arc flash study has been completed, the arc flash PPE requirements are labelled on the switchboard itself,” he says.
“We are also able to supply switchboards with protection relays installed. These can detect an arc flash, tripping the system faster than a circuit breaker, which minimises the energy released.”
“Main switchboards are controlling and distributing large electrical loads, so there’s no room to compromise on quality, safety, and experience,” concludes Steve.