The Future of Domestic Electrical Installations

gazza — Mon, 21 Oct 2013 23:00:00 +0000

gazza Tue, 22/10/2013

Many new factors are starting to affect the design and configuration of domestic electrical installations, such as the spread of green energy systems, the roll out of smart metering, the need for electric vehicle charging and the introduction of government initiatives like the Green Deal. Phil Dingle of Eaton examines some of the most important developments and explores their implications for contractors.
Traditionally, the design of domestic electrical installations has evolved at a relatively slow pace, often with the main driver for change being the introduction of a new edition of the IEE/IET Wiring Regulations. Today’s situation is, however, rather different, with multiple drivers for change forcing the evolution of installations to progress at a much greater pace. Much is being made, for example, of the introduction of smart metering.
The government has made a commitment to install smart meters in 30 million UK homes and small businesses by 2019 and, at first sight, it looks as if this enormous project should generate a lot of opportunities for electrical contractors. This may indeed be the case, but it’s far from certain.
Large organisations like British Gas have been awarded contracts for the meter replacement project, and it is most likely that they will use their own employees as far as possible, probably supplemented by additional staff hired in on short- or medium-term contracts. While it is possible that assistance will be sought from local contracting companies, this seems unlikely.
Although most contractors probably won’t be involved with the actual installation of smart meters, that doesn’t mean that there are no opportunities associated with smart metering. Homeowners with the new meters will have easy access, in real time, to detailed information about their energy usage and how much that energy is costing them.
Some will choose to ignore this information of course, but it will spur others on to investigate and hopefully invest in energy saving measures. Indeed, the roll out of the smart meter may well be the driving force for the wider deployment of home automation products and systems.
Astute contractors should be prepared to respond by offering home automation systems that provide efficient, effective and, where appropriate, automatic monitoring and control of heating, lighting and other functions. These systems can deliver impressive energy savings and could be an attractive investment for homeowners.
An important benefit for contractors is that the best home automation systems incorporate wireless functionality, which simplifies installation, reduces costs and opens up new options. Light switches, for example, that need no wiring and so can be installed almost anywhere without worrying about cable runs or disturbing wall surfaces.
The government is, of course, keen to be seen supporting energy efficiency in homes and to this end, it has recently launched the Green Deal which allows homeowners to borrow money to finance approved energy efficiency measures. The loan repayments are then added to the homeowner’s energy bills, with the idea being that these repayments will be offset by the energy saved.
Once again, this sounds as if it could create opportunities for contractors, but that may not be the case, at least not at the moment. The problem is that the software tools that have to be used to evaluate the energy saving measure in order to justify an application for a Green Deal loan do not currently favour some electrical control strategies – they are, instead, much more focused on the fabric of the building and biased toward things like improving home insulation and installing more efficient central heating boilers.
One area that is receiving government support and is of very great interest to contractors, however, is the provision of solar energy (PV) systems. The design and fitting of these systems is outside the scope of this article, but linking the PV system to the rest of the home electrical installation is not. Many modern consumer units make specific provision for the connection of an auxiliary supply from a PV system but there are additional requirements that must be met.
For safety reasons and to aid maintenance, solar PV installations must always include a dc isolator for power coming from the solar panels and an ac isolator for power flowing from the inverter. Surge protection devices are also recommended for both the dc and ac circuits. In the past, these requirements have usually been met using devices mounted in separate enclosures, but this approach unnecessarily extends the time taken to install and wire the system and increases costs.
A better solution is offered by combined PV switch-and-surge units, which comprise dc and ac isolators together with surge protection devices, all mounted and pre-wired in a single compact enclosure. With these, there is only one unit to install and the amount of wiring needed on site is minimised. Additionally, the contractor no longer has to select the components separately, taking into account their suitability for PV applications and their compatibility with each other.
Even for domestic installations that do not include a PV system, surge suppression – more properly known as transient voltage surge suppression (TVSS) – is an increasingly important concern, particularly after the introduction in 2011 of the most recent revision to the IET Wiring Regulations, which puts increased emphasis on TVSS.
It’s not hard to see why. Modern homes are filled with costly electronic equipment like televisions and computers, and even appliances like washing machines and cookers that were once purely electrical now have integrated electronic controls. Since all electronic devices are potentially at risk of damage from supply voltage surges, it’s clear that providing homes with effective TVSS is a wise precaution.
This is most definitely an opportunity for contractors, although it’s one they may need a little effort to develop, as many homeowners are unaware of the risks until the day a nearby lightning strike kills their expensive television or computer system.
It’s perhaps also worth mentioning that there’s a widespread belief that simple plug-in surge protectors are all that’s needed. They’re not. Good quality plug-in units can provide a degree of additional protection – although many cheap units are almost worthless – but comprehensive and dependable TVSS can only be achieved with properly chosen fixed protection units fitted as a permanent part of the home electrical installation.
Something else that is likely to become a significant part of every domestic electrical installation over the next few years is provision for charging electric vehicles (EVs). At present, there are a number of charging point options available that comply with IEC standards, but key areas still have to be resolved, such as what rate of charge will be the optimum choice for EV users. This will affect both the time it takes to charge the EV batteries and the installation cost. Currently 7.3 kW appears to be the preferred option, but faster options, both ac and dc, will also be available.
Possibly the best advice to contractors, therefore, is to make provision in the consumer unit for an EV charging circuit – bearing in mind that this will probably require a supply rated at 35 A or so – but not to install charging point equipment unless the homeowner actually has an immediate need for it, in which case the type of vehicle will probably dictate the sort of equipment to use.
If we now broaden the scope of this article slightly to encompass not only self-contained homes but also so-called houses in multiple occupation (HMOs), such as blocks of flats and student accommodation, two other important factors are influencing electrical installation design.
The first is an increasingly common requirement for all circuits to be equipped with individual RCBO protection, especially now that the cost of providing this has fallen as a result of lower prices for 6 kA RCBOs. Individual RCBO protection makes it easier to meet stipulations of the IET Wiring Regulations and, provided that all of the consumer units in a property are arranged in the same way, it also makes life easier for landlords.
When they receive a call from the tenant saying a breaker has tripped, they only need to ask which one. When the tenant replies, for example, that it’s the third from the left, they know instantly which circuit is affected and, therefore, the most appropriate course of action.
A second common requirement for installations in HMOs is sub-metering, so that each tenant can be individually and accurately billed for their electricity usage, something that is now very important with the high and continually increasing cost of energy.
Meters are often required to be MID (Measuring Instruments Directive) compliant, and most landlords now also ask for facilities for remote reading, either from a central point within the premises or from a separate location, such as the landlord’s office. Leading suppliers of distribution equipment offer options that make metering equipment of this kind easy for contractors to add to existing installations, or build into new installations.
As we’ve seen, domestic electrical installations are changing and becoming much more sophisticated. Features that are only seen occasionally at the moment, such as home automation systems and EV charging points, will become commonplace in the future. Many of the changes will create opportunities for electrical contractors to gain valuable business but, as we have also seen, there are some seemingly attractive opportunities that will, in all probability, benefit contractors little or even not at all.
To take full advantage of future opportunities, contractors will need to be flexible and enthusiastic about accepting change. They will also need support in addressing new requirements and, in some cases, new technologies. This support can best be obtained by working with a supplier that not only has proven experience in the field of domestic installation equipment, but also a strong reputation for combining quality and performance with innovation in its products.

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Eaton, Domestic Installations