Modern Building Services

FEATURE INSTALLER VIEW 18 MODERN BUILDING SERVICES FEBRUARY 2021 INSTALLER VIEW Overcoming the power distribution challenges of SHALLOW FLOOR VOIDS Paul Allen , from power distribution specialist, CMD Ltd, discusses the challenges of electrical distribution network installations in shallow floor voids and listed buildings. O ver the past 30 years, the amount of tech used in commercial buildings on a day-to-day basis has increased dramatically as working practices have made occupiers more and more reliant on IT equipment and the need to charge portable devices. This means more sockets are required across the floor plate, with sufficient capacity for resilience and futureproofing. In new builds, floor voids are usually designed with sufficient capacity for the level of services required. But even here, obstacles in the void, architectural features or a focus on maximising headroom can result in challenging congestion or inconsistencies in the floor void. In existing buildings, constructed before technology became such an integral part of the way we live and work, capacity in the floor void can be more of an issue. Heritage buildings in particular often feature varying void depths but a consistent approach to installing the power distribution is preferred throughout. Most common solution It’s an issue that electrical specifiers and contractors face repeatedly when planning the electrical infrastructure for commercial buildings. A busbar powertrack system is most commonly the solution of choice, because it offers speed and ease of use with plug and play installation. It also provides plenty of flexibility for reconfiguration, additional tap- offs on the network, and parallel UPS distribution, contributing to futureproofing strategies to accommodate changes in occupier requirements. A powertrack system is usually suitable for most floor voids of 50mm or more, but specifiers must be mindful of the need for additional clearance so that the building owner, occupier or facilities management provider can access tap-offs for maintenance or reconfiguration. While this does not present any challenges for many new build properties, for older buildings with more restricted floor voids or inconsistent void clearance, there is often insufficient space for a functional powertrack system. Often, specifiers assume that this leaves them with a choice of two onerous options: either to raise the floor and increase the void, or to opt for a hard wired electrical network. Both of these choices would add time to the programme and raising the floor could compromise headroom and heritage features too. That’s why there is an increasing appetite for a third option for refurbishment and heritage electrical distribution installations: power hub systems. Adaptable, Compact and Compliant Designed to offer plug and play ease and speed of installation comparable to powertrack systems, along with similar flexibility and futureproofing benefits, power hub systems are an ideal alternative where space is limited. They combine compact hub units with flexible metal conduits or ‘umbilicals’, which connect the hubs together to create the electrical distribution network. The flexible metal conduits provide cables with mechanical protection, allowing compliance withWiring Regulation 543.7 “Earthing requirements for the installation of equipment having high protective conductor currents”. They also protect cables from dirt ingress and rodents, ensuring a similar level of resilience to powertrack systems and ensuring that the electrical distribution system offers a lowmaintenance, fit and forget solution Power hubs are specifically designed for buildings where a conventional powertrack system cannot be installed due to lack of void depth or obstacles in the void. Not only are the units themselves compact, making them suitable for voids where height is limited, but the tap-offs are located to the side rather than above, whichmeans that they can no additional height clearance is needed for the removal, maintenance or addition of tap-offs.