Implications of the term 'recommended' in 7671

mapj1 said:

I would like to suggest to the court that had the plaintiff bears some responsibility, as had he ordered the fish, as was recommended, then his wife would not have been poisoned by the goulash, and the restaurant would not have burnt down later the same night as the defective hob would not have been used.

Of course that tongue-in-cheek scenario is specious nonsense.

I forgot to mention foreseeability. It was perfectly foreseeable that a diner would decline the recommendation. 

The next question must be whether an electrician would have breached the standard of care by not making the recommendation in BS 7671 known to the client.

David Stone said:

3A or more)

Isn't the current rating with reference to the performance of the AFDD itself, as specified in BS EN 62606 ?

Yes Graham, but an appliance with a tiny current rating is very unlikely to develop an arc of even this figure unless highly faulty, therefore the series arc detection is zero, and parallel ones are very unlikely as discussed. The question is then what are we trying to detect with most plug in appliances? We seem to be looking at white goods only and some are directly wired in anyway.

In a reply in the comments section for the video, efixx state that the doing nothing is not an option, comment, came from the person who wrote the definition of recommended in the regs.

that tongue-in-cheek scenario is specious nonsense

well yes. Except to provoke the thought, that the word recommend is not normally, nor in the regs,  used when declining is not a considered a perfectly realistic option.

M.

Eek, my head is spinning - too many negatives.

Lose one: the word recommend is normally, or in the regs, used when declining is not a considered a perfectly realistic option

Lose two: the word recommend is normally, or in the regs, used when declining is considered a perfectly realistic option

Agreed! 

sorry reading again  I agree my post reads like it's had the Humphrey Appleby treatment. (as in Yes Minister! - masters of the art of obscuration)

I agree with your simplification,.

M.

David Stone said:

but an appliance with a tiny current rating

The current is not always limited by the load components within the appliance, which may have failed (and hence have a lower impedance). That is a characteristic of a fault.

David Stone said:

and parallel ones are very unlikely as discussed

That may be the case for wiring, but not necessarily appliances - and there may be various causes for this. Worth looking at the expert witness report for Grenfell in this regard (and there were other protective devices, which did operate, but, if the appliance was the cause of the fire, did not prevent the fire).

David Stone said:

We seem to be looking at white goods only and some are directly wired in anyway.

I don't necessarily think "white goods only". I agree some may be directly wired in, but most UK appliances rated 13 A or less are supplied with a plug, and these days, usually moulded with instructions from the manufacturer not to remove the plug or flex, and only replace with the manufacturer's original replacement part (cue a rabbit-hole discussion as to whether that is right or not, and philosophising about what the relevant columns and ratings in Table 2 from BS 1363-1:2016+A1:2018 mean, and whether it's a conspiracy against re-wireable plugs ).

Now did anyone say that, but not a completely unreasonable discussion but not anything to do with BS7671! However I mentioned white goods particularly because they are the largest plug-in appliances. However an iphone charger is unlikely to sustain a 3A arc any longer than an AFDD takes to trip anyway.

The fire at Grenfell had both the RCD and MCB tripped I believe and neither prevented the fire. It is likely it was caused by ignition of refrigerant (propane), but we must wait for the full report to be sure (or sure-ish). The real problems were much worse and more complex than any fire in a single flat, which should not have escaped the containment zone under any circumstances.

To help users of BS 7671 understand the meaning of various words for the first time the Introduction provides help on this on Page 18 of AMD 2.

Hopefully readers will at least grasp the differences between Normative and Informative and Requirement and Recommendation?