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.

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.

mapj1 said:

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, I fully take your point and to some extent it depends upon the budget which is available.

I don't think that I am in immediate danger, but JP may disagree because I have Federal Electric boxes!