This is a very interesting debate.

Are AFDDs (inclusive of RCBO) a good idea. Yes....However


Been used is Germany for about 10 years now so they are not really a new technology.

It will protect against one type or Arc not both Series and Parallel

The AFDD is to help protect against issues created by substandard electrical appliances being purchased in the UK from abroad and especially on the Web (look up underwater 4 way extension leads on Ebay, Amazon or Wish)  



BUT
AFDDs could and will trip on nuisance devices thus causing nuisance tripping
Medical or Life critical system should not be connected to AFDDs resulting in no power.  A lot of Medical systems with have secondary power supply of even a battery backup

I strongly believe that better fire detection should be implemented like all dwellings having interlinked smoke/heat alarms as is the case in Scotland.  



I look forward to the AFDD debate continuing

The situation in Germany is interesting - AFDDs first appeared in VDE 100 in 2016, and after a short period of grace for the old regs they became compulsory for sleeping accommodation, old folks homes und Kinder Gaertner, places storing flammable materials etc. and such installation was mandatory to claim compliance with the regs.

As in the UK the German wiring regs are not strictly a legal requirement, but many things mean they may as well be, and unlike in the UK you will need good luck in finding a German Sparks willing to deviate far from the text.. So in they went at least on the new builds.

However, from 2019, there has been some serious mud thrown into the water, as the installation of AFDDs is now just one of a range of measures that may be taken to reduce the risk of fire, and not always the main one, and a risk assessment is recommended  to decide the best course.

I presume this is to allow their omission for cases where problems of unwanted tripping would cause more harm than the possible good or where  other measures (fire supression/ sprinklers or buildings made of concrete ?) mean a serious fire from an arc fault is most unlikely.

There was fairly heated  discussion in the German trade apparently when they came in, but I am mostly out of that loop these days (example here)

Now in reality, having spent a few years to get folk attuned to the "AFDDs good" message I will be surprised if there will  now be a rash of Germans taking them back out, but  it does show a highly  unusual trend for Germany, that of rowing back on a hard and fast rule....

Source here - in German of course.  A non-German speaker may feed the paragraphs under the section titled "Einbau von AFDDs nicht mehr verpflichtend" into google translate for more.

I am still looking for the evidence of fire reduction, but as yet it is not showing through, either in the US figures or in the German ones...

Mike.

Edited for Grammer ' A non-German speaker..' apologies

mapj1 said:

Source here - in German of course.  non German speaker may feed the paragraphs under the section titled "Einbau von AFDDs nicht mehr verpflichtend" into google translate for more.

Or open the page in Chrome or Edge and the option to translate the web-page to English will be provided.

In my opinion at present time for a dwelling a CU would be good with all RCBOs and SPD type 2 & 3 until there overwhelming evidence to the contrary.  This should be the case for a home or a rental.  I also feel that in the UK well England we needs to increase fire detection in the average home and rental sector by interlinking smoke/heat/Carbon monoxide alarms. 

This does again pose another question.

Fire/Smoke alarm.  Advise is to exit property

CO alarm. Advise is to open all windows and exit property

I would suggest a highly distinction sound for smoke/heat to CO alarm would be advisable.  The interlinking of the CO and Heat and Smoke means there is a greater chance of detection as some fires give off more CO before there is smoke, while other fires give off more heat before flame. 

Sergio Fernandez said:

In my opinion at present time for a dwelling a CU would be good with all RCBOs and SPD type 2 & 3 until there overwhelming evidence to the contrary.

Ah yes, the £1k fusebox!

Would you not have a CO alarm only if there are solid-fuel or gas appliances in the house itself?

To justify a 1k per fusebox change on safety grounds, instead of not doing it and spending the saving on some other more effective safety measure (perhaps new tyres and brake pads on the car ?) you need something like 1 in 1000 installations to actually kill someone if you don't do it, (assuming £1 million per life - you may double this if you like, it has little effect on the conclusion - then you need 1 in 2000 thousand fuseboxes to be deadly dangerous...) In the UK the rate of electrocutions and fires are nothing like that bad over any sensible period. In fact they are not even that bad in places where earthing is optional and wires aer twisted together instead of in connectors.

By all means make the change on cosmetic grounds, or ease of use, or change of load, but  not immediate danger. It is important to keep a grip on the figures and why we do things.

Mike.

a 10 way board with SPD and fully populated with RCBOs is about £150 have a look at Verso or CP FuseBox, Its the AFDD board that reach a £1K

Good question on the CO alarm.  Yes people only fit them in a rented property if they have solid-fuel or gas appliances in as this is now a legal requirement but I do think that the average home owner should also follow the same rule of CO in room with  solid-fuel or gas appliances.  Additionally heat detectors should also be mandatory in kitchens.

Another question for discussion

In flat which does NOT have solid-fuel or gas appliances in the block of flats a that do have solid-fuel or gas appliances

CO detector would also be beneficial as CO can enter from outside or from the communal areas.

(To test the theory have a look at blocks of flats in your area, spot the exhaust flue on outside of building and then see how close it is to and airvent or window of that property or another property) 

Sergio,

Your detail all sounds great! ( In Theory), Now being a engineer based and living in Scotland where legislation now dictates that all dwellings must have hard wired smoke/heat/CO detectors and all interlinked or all interlinked but long life battery operated that comes at a big cost!!

Firstly home owners, letting agents etc need to know about the legislation and when it comes into affect, and the Scot Gov made a right pigs ear of that so much so the deadline dates changed.

Secondly the home owner, letting agent needs cash/funding to install the appropriate devices and pay somebody competent to do so.

Thirdly the devices need maintained.

Fourthly according to legislation a home owner may run into issues if they try to sell the property without the right number/type of detectors and all working. So surveyors may identify no appropriate detection that could prevent a sale going thru or more likley the buyer will want a discount on selling price.

Now personally, I went out and bout wireless 10 Year battery units, so three CO detectors, two fixed rate of rise heat detectors and five smoke detectors, all fitted in correct places based on the legislation, the devices cost me just over £700!!

As Im capable of installing myself the labour charge was nothing, so far so good.

But what "Benefit" is there in this legislation to me and what you imply? and please answer that question. As a time served craft electrician with the practical and qualifications I have now and working in the fields of compliance and standards of work. Im sure you can guess the electrical installation in my home is as good as it can be, designed, installed and maintained by a competent person. I cant say no electrical from of ignition would never occur but its certainly as low as it ever could be.

Under the old Scot Gov legislation and being competent I had battery smoke and heat detectors and CO detectors anyway, and when the alarmed to say battery needed changed I did that.

So Im now £700 + out of pocket and for what benefit?? as the condition of the electrical installation in my home and equipment hasnt changed. But I have complied with the Law.

My gripe and complaint and issue is, the cowboy electricians/contractors poor design and use of incorrect materials and non compliance of stadards for electrical installations will still all happen and those property owners that go down that route will certainly not be fitting £700+ of detection equipment after all when they work the fire has already started.

So to me its like saying everybody fit seatbelts and airbags but do nothing about driver skills and competency and road conditions. By the time tthe seatbelts and airbags have worked you have already crashed the car.

As members of the IET and those of us that may influence policy and legislation is lets make the installations safer so some of these modern devices are not needed, rather than how things seem to be accepted of lets put in these devices because we know the deisgn/installation and verification of the installation is crap.

Lets get this in the right order first please.

Cheers GTB

GTB said:

So Im now £700 + out of pocket and for what benefit?? as the condition of the electrical installation in my home and equipment hasnt changed. But I have complied with the Law.

Move south, young man! ;-)

GTB said:

So to me its like saying everybody fit seatbelts and airbags but do nothing about driver skills and competency and road conditions. By the time tthe seatbelts and airbags have worked you have already crashed the car.

Well, would you drive a 90-odd year old car with no belts (forget airbags!), rigid steering column, no crumple zones, etc?

I agree with everything that you say. Now I really must get around to installing those alarms just in case the house catches fire at night. (What use are alarms during the working week?)

Sergio Fernandez said:

a 10 way board with SPD and fully populated with RCBOs is about £150 have a look at Verso or CP FuseBox, Its the AFDD board that reach a £1K

Yes well, cheap tyres are available too, but I wouldn't put them on my car.

Sergio Fernandez said:

(To test the theory have a look at blocks of flats in your area, spot the exhaust flue on outside of building and then see how close it is to and airvent or window of that property or another property) 

You may be correct, but I think that such an installation would not comply with the building regs.

Sergio Fernandez said:

a 10 way board with SPD and fully populated with RCBOs is about £150 have a look at Verso or CP FuseBox, Its the AFDD board that reach a £1K

Yes well, cheap tyres are available too, but I wouldn't put them on my car.

Sergio Fernandez said:

(To test the theory have a look at blocks of flats in your area, spot the exhaust flue on outside of building and then see how close it is to and airvent or window of that property or another property) 

You may be correct, but I think that such an installation would not comply with the building regs.