Is there anything new left to develop with the good old consumer unit? EC&M finds there is plenty keeping the manufacturers busy.
Modern day consumer units are a world apart from the fuse boards that were once the common form of circuit protection in the home. Not only are protective devices increasingly sophisticated nowadays but, especially in new build houses, the positioning of consumer units in visible locations means that they need to look good too.

But what are the latest innovations being unearthed by the electrical design boffins at the leading manufacturers? MK Electric is about to release its first redeveloped consumer unit enclosure for 15 years. How does it propose to stay ahead of the fierce competition in electrical equipment both at home and from imports from the likes of the cheap and cheerful Far East?

"When looking for inspiration in the design and development of MK's new range of consumer units, we started by asking our customers their likes, dislikes and needs for the future," explains John Storey, strategic business manager with MK Electric. "The research carried out amongst installers, specifiers and end-users allowed us to design a range that meets all their diverse needs, both in terms of product design and the commercial package that this represents. In addition, it gave us the opportunity to understand where we and others had been successful in the past and similarly, rectify any shortcomings of currently available ranges," adds Storey.

One of the key findings of MK's research amongst new house builders was the desire for a better looking product to hit the market. Many features determine an aesthetically acceptable design, but colour, size and shape make the most immediate impacts. Despite attempts by some suppliers to use these elements of consumer unit design to make a feature of the product, MK's interpretation of customers' needs is more restrained. "The new consumer unit is designed to blend in with its environment. Hence, magnolia, a warm but neutral colour has been chosen to help keep the unit discreet," explains Storey.

Developers were also critical of the "mission control" look of existing units, with devices being openly visible to homeowners either through a clear lid, or in some cases no covering lid at all. Despite their critical nature in providing the function of protection, many specifiers felt that their visibility was unsightly. Although not a new idea, the updated range comes with a matching magnolia lid to hide the protective devices. "This lid is also downward opening to allow the positioning of circuit and test labels within, rather than on the fascia of the unit itself," adds Storey.

According to MK's market research, most consumer units that are currently available are perceived to be 'angular', 'solid' and 'chunky'. This can often be seen to give a reassurance of quality. However, as all units available sold in the UK need to meet the stringent BS EN requirements and be tested in an ASTA-approved environment, installers, specifiers and users often already assume this level of quality. Therefore, "MK's new design has introduced curved lines not only to make the unit look more contemporary, but also to allow it to blend in to its environment," explains Storey. Similarly, readily available flush-mounting options give the specifier and installer even greater opportunity to minimise the obtrusiveness of the unit.

Size matters! Specifiers and users are asking for the minimum size possible, while installers need generous amounts of wiring space to ease installation and provide a neat job. This can be a difficult conundrum to resolve.

Some of the smaller units on the market can give installers a tough time routing cable and making good connections, while those with greater wiring space can just look much larger all round. "The current unit had found many loyal installers due to the amount of wiring space it provided, however the need to reduce the overall dimension while maintaining the wiring space was a key element of the design brief for the new units," says Storey. The new units have a reduced footprint of over 10%, along with a low profile to meet the aesthetic needs of specifiers and users, but the usable wiring space has been maintained by slightly offsetting and raising the DIN-rail. So despite reducing the overall dimensions of the unit, installers should find the wiring space that they need.

Flexible installation
Most consumer units come complete with a switch, rcd, or indeed most often with both for split load installations. With split load units becoming increasingly popular, it can often be limiting to choose a consumer unit that doesn't offer the installer the ability to arrange the protective devices exactly as the job in hand requires. MK's flexible floating busbar system allows for last-minute on-site changes to the installation, which saves time, money and any inconvenience to the client.

"A consumer unit system based on flexibility enables the contractor to carry fewer enclosures plus a selection of devices that can be assembled on site to almost any configuration," points out Storey. "Our new range of consumer units retains this important feature, while also providing ample 360° cut-out points and open cable entry at the rear."

Whenever a manufacturer looks to re-design a consumer unit range, concerns are raised over the compatibility of the new design with the old design and the usability of devices between both old and new ranges. The new unit has been designed to fully accept MK's current range of devices, which aside from a wide range of rcds, mcbs and control devices, now also includes the space- saving single module rcbo for single circuit over current and earth leakage protection.

Given the ever-increasing demand for electricity in the modern home and its protection and control, the larger installation requires ever more available capacity. Recognising this requirement has led MK to develop larger insulated units with the introduction of a 21 module unit. "However, the 'sideways' increase in capacity does not always meet the needs of restricted horizontal installation space," says Storey. "Therefore, there is also now the option for vertically stackable units in 12, 16 and 20 module sizes. In this format dual-rail, insulated units become both more attractive and cost-effective than the traditional metal units offered by many suppliers."

When adding to existing installations for house extensions, conservatories or to deal with new appliance installations such as electric showers, smaller units have become a cost-effective and popular way of extending the electrical installation. To this end a four module unit is now included in MK's portfolio.

Where a large number of consumer units are to be installed to the same specification in a major new build or re-wire project, the contractor may find it more useful to have them pre-assembled in the manufacturer's factory. This factory built service can save valuable on-site time and, as with MK's service, it is sometimes offered free of charge for a certain quantity of units.

Clearly there is life in the old consumer unit. In fact, given the pace of change in today's installations, perhaps it is will be rather less than 15 years before the design boffins are at it again.