Do we have to fit AFDD's in domestic installations?

[HappyHippyDad]

I can't find any really up to date threads on whether we have to fit AFDD's.

I am specifically talking about in a domestic premise. I can see that 421.1.7 shows where an AFDD HAS to be fitted (i.e in one of the 4 bullet points), but then it says below ( the bullet points) it is 'recommended' that AFDD's are fitted in ALL premises for socket outlets.

The Napit Webinar (02/11/2022) kind of skips lightly over this point. At 11 mins and 25 seconds he says something along the lines of 'it is up to the designer whether to use the recommendation of using AFDD's'.

It clearly is not mandatory otherwise the reg would not state the 4 examples of where it actually is mandatory. So it is actually optional, but there isn't any criteria given to help you decide whether or not you should fit one.

Does anyone have any clarification on this?

 

[brianmoooore]

Anything other than this is a recommendation which means it does not need to be done

Right up to the point when something disastrous happens that is determined wouldn't have happened if an AFDD had been fitted

 

[default]

Right up to the point when something disastrous happens that is determined wouldn't have happened if an AFDD had been fitted

As long as you have followed the regulations and don't decide yourself what constitutes as a recommendation then there is no come back. The regs aren't there to trick you. They may seem to contradict themselves sometimes but a recommendation is a recommendation. When it comes to AFDDs they state where you shall you them, and even define what they mean and the recommend where else they could be used. If you decide that your not sure then use them everywhere then you won't need to worry.

 

[mainline]

Ive just put a board full of afdds on a thatch re wire as im not on a price so thought even if it gives 1% extra safety im doing it, (im an ex fireman and they burn well ) but the rest of my jobs i wont, they do have Bluetooth though so you can communicate with them with your phone with the hager app

You will have to let us know if they give any problems.

 

[newfutile]

Recommended does not mean you have too,however i always plan a defence in case this is questioned at any time .mine would read : it does not state “shall” (unless it does) ,good workmanship ,following equipment manufacturers instructions , checking all screw fit joints and of course proper inspection and testing with all results as expected or calculated . You could probably go further than this with proper cable supports,safe zones rcbos. For lighting for instance a series arc current (with led lamps) will most likely never be reached .

 

[pc1966]

Ive just put a board full of afdds on a thatch re wire as im not on a price so thought even if it gives 1% extra safety im doing it, (im an ex fireman and they burn well ) but the rest of my jobs i wont, they do have Bluetooth though so you can communicate with them with your phone with the hager app

That is a very good example of where AFDD would be a sensible choice even though nor mandated.

Also I suspect owners of thatched roof properties can probably afford it, if not then they can't afford to maintain the thatching!

 

[HappyHippyDad]

Update from napit technical team relating to when you have to fit AFDD in domestic premises and it's view on the term 'recommended'...

"Thanks for watching the AFDD webinar, we are pleased you enjoyed it. The term recommended is not a new requirement for AFDDs, if you refer to the 2018 Edition of BS 7671 (blue copy) Reg 421.1.7 recommends AFDDs for all AC final circuits. Unfortunately, with so many different installations and different user types it can only be a decision made by the designer after considering all aspects."

Basically they're saying it's up to us if we fit them. In reality, hardly anyone will fit them at present due to the cost. If there is a fire due to electrical arcing and it goes to court, the IET will say 'well we recommended it." A disappointing reply to my thorough question (although I pinched the wording from @Julie 's professional sounding post )

I think, as part of my quote I will recommend AFDD's to be fitted. I'll perhaps write a small amount about there use, and then leave the customer to make the decision.

 

[Dustydazzler]

Never fitted one and until they become common place at less than 1/2 the price I won't be fitting any

 

[HappyHippyDad]

Never fitted one and until they become common place at less than 1/2 the price I won't be fitting any

Neither will I Dusty, but the point being... If there is a fire due to arcing then it will be the electrician who is deemed to be at fault because the IET have covered themselves with the word 'recommended'. I will now continue this bottom covering exercise by also adding the word 'recommend' in my quote.

Then, in 2-5 years we can all fit them as standard when they come down in price.

Then, we can all talk about the latest addition to the rcbo/afdd, with something else added to it which costs a fortune etc etc .

 

[Midwest]

Wonder if an AFDD would of worked here

 

[brianmoooore]

RCD would have taken care of the above.

 

[newfutile]

If it was a serial arc then no, low current arcs are not detected,in the USA maybe as there current will be twice ours for the same wattage

 

[brianmoooore]

May have started with a serial arc, but there's enough carbon there to leak sufficient current to the cpc to trip a RCD.

 

[mainline]

May have started with a serial arc, but there's enough carbon there to leak sufficient current to the cpc to trip a RCD.

Maybe not before catching the house on fire, though.

 

[7029 dave]

Dave tight is better than any torque screwdriver or any AFDD's

 

[Dustydazzler]

DELTIGHT

 

[Midwest]

RCD would have taken care of the above.

Not continuity between cpc & line in this fault.

 

[LukeD]

Ive got a EICR to do today that requires measuring the building height ( floors ) to see if it come under HRRB regs and needs AFD’s

They better hope its under 18m !! Otherwise its 5x new AFD and thats not cheap !

 

[Markyd]

I live in a timber clad and old oak barn conversion. It has been fully rewired to a high standard. Because of multiple buildings, we have multiple CUs, all Hager. We recently decided to fit AFDDs to all areas where we have any kind of fire risk concern and had no difficulty getting them via our trade accounts. What is interesting is the resistance to using them which I think is largely driven by cost. We paid £102 each, plus fitting and testing and some other necessary changes due to CU space. This is not a trivial sum for AFDD multiples in domestic properties. I am a developer, not a qualified electrician, though I am familiar with the regs. If the regulatory authorities think AFDDs will materially reduce fire risk then having vague wording like "recommended" is ridiculous. Eventually insurance companies will drive this. I specify them in developments now. They make sense to me.

NOT HAGER my god anything but them....they dont even trip when they are nearly on fire

 

[davesparks]

Ive got a EICR to do today that requires measuring the building height ( floors ) to see if it come under HRRB regs and needs AFD’s

They better hope its under 18m !! Otherwise its 5x new AFD and thats not cheap !

Not necessarily 5x new AFDDs, that would only be a C3 and so a recommendation, not a requirement.

 

[davesparks]

NOT HAGER my god anything but them....they dont even trip when they are nearly on fire

That's a very extreme statement, do you have much evidence for this?