Signs Your Consumer Unit Needs An Upgrade.
When ensuring safety with consumer unit replacements, picture the scene. It is the Summer of 1985 in the United Kingdom. Live Aid has just raised tens of millions with historic dual concerts in London and Philadelphia. Scientists discovered the Ozone layer. Rogers Moore’s last turn as James Bond comes out in cinemas. Unemployment falls by about 100,000 jobs. Whoever was living in your house at the time has just been handed an illegible paper certificate for the rewiring of all your circuits and upgrade of your consumer unit, by an electrician wearing fashionably small football shorts, smoking a Benson and Hedges Gold cigarette which is at risk of setting his perm a blaze. Life is good.
However, that was forty years ago, and so long as the installation was good, we have just arrived in the middle of 2025, and at the end of the average design lifespan of your electrical installation. Your fuseboard may look a little like this.
The Replacement Process: What to Expect
So long as you were competently wired from around the late 70’s onwards, there’s some good news. That is around the time we figured out the best way of making domestic twin and earth cable (BS6242Y), and we still make it the same way today. The solid copper cores and chemical make-up of the two insulation layers mean that, well-installed and not abused, it could and should last forever. Thus, the first step in our process, testing.
We are engineers. We like data. Numbers are our clay, and without clay we cannot create (I think I’m loosely paraphrasing Sherlock Holmes here). It is sensible for us to first test and inspect the existing installation, using an Electrical Installation Condition Report. There are a few reasons for this, but the big one is that we have to prove the installation is safe to power up, because we’re powering it down and therefore taking general responsibility for it. There’s a possibility that some other essential repairs need to take place as part of the consumer unit upgrade, such as installing or improving main earth bonds to your incoming services, or swapping the light in your bathroom for something more appropriate. For more on EICR’s see here.
With the consumer unit upgrade as with the EICR, you can expect a certain amount of time without power; figure out how to hotspot your laptop to your phone (and which room you get decent enough signal in to handle a teams session), ensuring said laptop is charged, fill a thermos with boiling water if you require a cup of tea every 30 minutes, that kind of thing. Some customers take the opportunity to pop out to that nice Italian family-run deli/cafe up the road for a big sandwich that is considered a little treat. Also, if you have a toilet in your house that relies upon a macerator as part of its waste removal method, well worth sticking some ‘Police Line Do Not Cross’ tape across that particular door.
Please also expect some drilling, a small amount of manageable dust, and an electrician’s straitened leg poking out from your under-stairs cupboard because of cramp.
Benefits of Modern Consumer Units
Due to the ever-evolving nature of construction and technology, our safety services have to stay in lock step if these fascinating new technologies are to be installed in Britain’s homes.
Starting basic, we’ve gone back to metal fuseboards. Prompting amendment 3 of BS7671:2008 in 2015, a fire took place that started within a consumer unit due to a loose main neutral connection. Good maintenance and regular inspections are one way of protecting against this, but the non-combustible consumer unit chassis is a good backstop. Our general manufacturer of choice is Contactum, but we may decide another is more appropriate on occasion.
“Additional protection via an RCD rated at no more than 30mA for all circuits with socket outlets up to 32 amps”, we’ve been doing for a little while. Whereas a traditional circuit breaker looks for overload, due to a circuit drawing more current that the circuit is rated for or because of a large fault current caused by a cable ‘short’, and RCD looks for imbalance; it looks at what goes out on live, what comes back on neutral and if that figure doesn’t match enough, it trips. We’re moving away from ‘split load’ consumer units with one RCD looking after a bank of up to 10 circuits, favouring combination over load and RCD devices, mainly because it means that in the event of a fault, only a single circuit is lost, rather than half the gaff. Also, a lot of equipment ‘leaks’ a small amount of current to earth by its nature, and a little bit on each of the circuits can cause a nuisance trip of that main RCD, which was only doing its job and is now unfairly labelled a ‘nuisance’ due to poor design!
On the subject of RCDs or Residual Current Devices, they come in a few types.
- Type AC
- This is only suitable for basic old-school resistive loads such as filament lightbulbs, toasters, kettles, immersion heaters, etc. The moment a circuit board is involved, there’s a risk that it won’t even work.
- Type A
- These are what we’re most commonly installing now, within the domestic market. Modern electronic devices (see anything with a circuit board from your washing machine to your TV) leak some pulsating DC (the electronic waveform, represented as a straight line) back into the AC waveform (how electricity is supplied to your house, represented as a sinusoidal or wavy line). This DC leakage affects the function of the Type AC RCD device, blinding it. The Type A RCD is good for around 6mA of DC interference, which is a reasonable amount, and therefore, the devices are reasonably priced.
- Type F
- Essentially, the Type A RCD’s muscular better read sibling. It’ll do 10mA of DC waveform, in its various forms, whilst also monitoring a multitude of additional residual current faults in differing combinations across multiple conductors. I wouldn’t be at all surprised if we moved to these once the technology is a little more reasonably priced.
- Type B
- The best, and costed as such. It does it all. Even if you have kept up with me so far with the terminology and such, I fear I’d lose you here, rest assured that they do loads. Certain scenarios will call for them, and that would be the time to learn about why you’re spending upwards of £300 on a circuit breaker. For the time being, unlikely to be installed in your new consumer unit.
Arc Fault Detection Devices
Also known as AFDDs to their friends and lovers of acronyms, these are a recent addition to our arsenal of protective technologies. They detect arcs, which is when electricity ‘jumps’; baby lightning in your home, that generates a lot of heat. Allegedly, having one of these in play would have stopped the faulty freezer that was the ignition point for the fire in the Grenfell Tower, but that’s a whole other conversation. How they work is that they keep an eye on the waveform that is flowing through them, and in the event of a ‘serial arc’, they trip. Worth noting that the regulations as they stand only declare that these are a SHALL INSTALL in residential nursing homes, HMOs, Rise Buildings and student accommodation (places that are tricky or slow to evacuate). In the UK, we still install ‘ring circuits’, which were invented by none other than Winston Churchill. Ring circuits can cloud the effectiveness of AFDDs by hiding these serial arc waveform bumps across the other leg of the ring from where the fault is, so if we’re going to be super safe, we may have to start letting go of the man with the cigar.
Surge Protective Devices
These are reasonably priced, come with a lot of fuseboards as standard and in the event of a voltage peak from the grid larger than 263V, dump the voltage to earth by creating a lower resistance path than your Macbook charger or fridge freezer, in the hope of not blowing them up. Usually, a combination of Types 1 & 2 will be installed, but you definitely will want a Type 1 upfront if you have a TT earth system (generally because of overhead supply cables and the likelihood of damage or lightning. While on surges, using a type 3 multiblock extension lead for your home work station or entertainment centre isn’t a bad shout.
Compliance with Current Regulations
An Englishperson’s home is their castle, and so long as you are still living that glorious summer of 1985 and have made and will make no changes to your fixed wiring, you still comply. And also, it is your house, so long as the safety of your neighbours isn’t affected, you can do what you want, and the regulations are not applied retrospectively. But, if you are to make alterations or additions to the current setup, it should be to the latest version of BS7671, and as such probably worth upgrading your consumer unit appropriately.
If you are a landlord, multiple legislation suggest that you should be doing everything that is within your power to ensure that the property that you let out is safe for habitation by others. You will already be getting regular EICRs (or would be wise to start now) and as such will be getting recommendations for safety improvements to the current standard. Imagine being asked by a judge, should the worst happen, whether you did everything that was reasonably within your power to prevent the incident from occurring?
If you are a landlord of an HMO, please see the above, but with AFDDs.
Get a quote for your consumer unit upgrade today!
To find out more, contact Pretty Wired on 020 4542 1890, email us at info@prettywired.co.uk or send us a message here.
