Choosing the Right Level of Safety for Your Home
RCBO consumer wdwdIn any building you call home you'll have an electrical system that powers your lights, appliances, and devices. This wiring system will be managed and safeguarded by a distribution box, commonly referred to as a consumer unit.
This consumer unit is intrinsically connected to your home's electrical wiring, continuously monitoring for electrical faults ready to cut the power to keep you, your loved ones, and your property safe.
As new safety devices are developed, wiring standards are updated to include these devices. Whilst there are benefits, there are also pitfalls. Driven largely by the cost of any new tech, the application of these devices have yielded various setups over the years which have changed as costs have come down.
Each setup with RCD’s installed have different benefits and different outcomes in the event of a fault. Depending on the setup, you could either lose all your power when a lamp blows, or have the power fail to just one circuit.
Let’s take a look at the setups, and then we can explore what each of them are and what they mean if you have that type fitted.
Setups of Consumer Units:
1. Main switch only Consumer Unit:
What is it?
Simply put, it’s a unit comprising of either fuses or switches with no RCD capability.
How to Identify:
Every unit will have a main switch. It will either be on the left, the right, (or rarely) in the middle. It’s a simple switch that goes up and down. It won't have an additional little switch with a ‘T’, or ‘Test’ inscribed on it.
Safety Level:
Minimal
Units with no RCD protection offer protection for your homes electrical system. It protects your wiring only. There is no protection against faults that could lead to potentially fatal electric shocks.
2. Overrated RCD Consumer Unit:
What is it?
RCD’s are rated at different levels. The various levels protect different things. RCD’s installed to protect people should be rated at no more than 30 milliamps, sometimes presented as 0.03A, or 30mA. If you have an RCD at your unit that is higher than this, then you may still be at risk of electric shock.
How to Identify:
These switches will have a ‘T’ or ‘Test’ button on them. Depending on where they are fitted into your unit will depend on what they protect.
Safety Level:
Very Low
While they offer some protection, overrated RCDs are fitted with a view to protect wiring, or to compensate for a poor connection to earth on the supply cable coming into your home. Neither of which are designed to protect people from electric shock.
3. RCD Main Switch Consumer Unit:
What is it?
Assuming we do have an RCD that is rated to protect people, RCD main switch units benefit from protecting all the wiring in the home by having this RCD protection on the main switch supplying the consumer unit.
How to Identify:
Your main switch, (located at either end or in the middle of your consumer unit) will have a ‘T’, or ‘Test’ button on it.
Safety Level:
Low
RCD main switch units provide protection against electric shock. A major pitfall is that if you have an earth fault anywhere on your wiring, the power to the entire home is cut. At worst, until the fault is identified and either removed or repaired, you may not be able to get any of your power back on.
4. Split Load Consumer Unit:
What is it?
Split load units started being put in at the end of the 90’s. The idea was to install RCD to socket outlets. Lighting and fixed equipment like ovens and hobs were not protected.
How to Identify:
Split load boards are quite distinctive. They will have a Main switch (this time, only at the right or left) and then an RCD switch in the middle. Split load boards were rarely fitted with RCD’s rated more than 30mA, as at this time RCD’s had been adopted as protective devices for people.
Safety Level:
Low
Split load units offer protection against faults with socket outlets. Therefore, you should be better protected from shock risk if using plug in equipment.
5. Dual RCD Consumer Unit:
What is it?
The dual RCD is as the name suggests; a unit with 2 RCD’s. Once the industry decided to protect all circuits with RCD, these boards became very popular.
How to identify:
Dual RCD units have two RCDs, each protecting a group of circuits. You can identify them by the presence of two RCD switches.
Safety Level:
Medium
Dual RCD units offer increased safety because all the circuits benefit from RCD protection. In addition, the RCD switches break both the live and the neutral ensuring isolation of the faulty circuit.
6. Hybrid Consumer Unit:
What is it?
Hybrid boards are the first setup that use RCBO’s. RCBO’s allow for each circuit to have its own RCD protection, eliminating the problem of multiple circuits being affected during an RCD related fault.
How to identify:
Expect to see individual test buttons on each of the individual circuit breakers. These buttons are pushed in, unlike the lever that operates the circuit as an up or down.
Safety Level:
Medium
Hybrid units offer more precise protection for individual circuits, reducing disruption by allowing more circuits to stay energised
7. Full RCBO Consumer Unit:
What is it?
This setup does away with conventional RCD’s. An RCBO unit will have individual RCD protection for each of its circuits. This means an earth fault on 1 circuit only switches that 1 circuit leaving the power on to everywhere else.
How to identify:
Full RCBO units will only have circuit breakers with the on/off levers and the RCD test button on them.
Safety Level:
High
Full RCBO units provide the highest level of safety as each circuit has its dedicated protection, making fault identification and isolation efficient.
8. Full Double Pole RCBO Consumer Unit:
What is it?
The only difference between this unit and the previous unit is the advent of double pole switches. To look at them you wouldn’t know the difference, but double pole RCBO’s are considered excellent because of their ability to cut the live and the neutral conductors of a circuit at the source.
The neutral conductor has been in the spotlight recently within the industry because of a number of faults that have caused serious injury to people. Cutting the neutral as well as the live at the source is a really smart thing to do.
How to identify:
Its not straightforward. All devices will have the details on them, either and item code that you can put into Google which will then bring up the specifications which you will then have to go through to establish whether it is single pole or double pole, of which is sometimes printed on the side of the device which may require removal from the consumer unit to establish.
Or; you can use a test instrument to establish if the neutral conductor is in fact being cut when the device is in its off position.
If you are unsure as to whether you have double pole or single pole devices, I would suggest that you have single pole. There are literally one or two devices on the market that are double pole RCBO’s for domestic consumer units. Whilst this may change in the future, as I write this in November 2023, there is only one that I have found that is commercially available which I now fit as standard to all new electrical systems and consumer unit changes.
Safety Level:
Very High
Due to the added feature of double pole isolation, Full Double Pole RCBO Consumer Units take the number one spot as being the safest consumer unit on the market for domestic circuit protection
Conclusion:
Knowing which unit protects your home can be a good starting point when deciding if its time for an upgrade. The higher the safety rating you wish to achieve, the higher the costs can go. Many customers see enormous benefit in Full RCBO's because there is minimal disruption in the event of a fault. Other customers are less concerned, and happy to simply have the safety devices installed in the most cost effective way.
Meet Benjamin Grant, a career electrician with two decades of experience in the field. Benjamin is not your typical tradesman; he's a consumer-focused visionary who understands that your home is more than just a structure; it's an expression of your unique lifestyle and personality.
With a passion for helping customers realize their vision for the perfect home environment, Benjamin is committed to harnessing the power of electricity in smart and thoughtful ways. His goal is to make your home not just functional but a haven that reflects your dreams and aspirations. Whether it's creating ambient lighting, integrating cutting-edge technology, or optimizing energy efficiency, Benjamin brings a wealth of knowledge and innovation to every project.
So, when you embark on your next home renovation journey, remember that Benjamin Grant is your trusted partner, ready to turn your electrical dreams into reality. With his expertise and dedication, your vision for the perfect home is closer than you think.
