Insufficient overload protection on circuit

[ShaunShep]

5s disconnection is permitted for a 40A circuit supplying a cooker if there is no socket outlet, although in reality it will be the same disconnection time as the others.

Type A is just the type of cable, flat PVC insulated and sheathed in this case, which is the most common type used for domestic wiring.

Without the installation method, there is no way to determine if the cable will be subject to overload.
6mm² can be rated up to 47A if surface clipped or in masonry. Substantially less if installed through insulation or other arduous environments.



View attachment 278714
Some EICR documents are better than others.

As for how - reference to the original installation certificate and other previous documentation if available.
In the absence of that it's either a case of looking, or it's a limitation, which may lead to other problems.

The cable runs through the kitchen ceiling, and is pinned to breeze blocks, with dot and dab boarding over the top.

 

[conny]

We've just come back from a 3 night stay in a converted barn. Lovely place, 6 double bedrooms, lounge, games room etc and indoor swimming pool. Range style electric 5 element hob & double oven protected by 20A RCBO My wife and daughter were cooking a big roast dinner for 12 and wondered why the potatoes were taking so long to boil. I had a look and realised the RCBO had tripped. Not surprising as she was using 4 rings and both ovens.

 

[flameport]

That almost certainly qualifies as Method C, which means a 40A protective device is suitable.

 

[JohnW2]

Some EICR documents are better than others.

So it seems but, as you will realise, what I was illustrating was the BS7671-recommended one.

As for how - reference to the original installation certificate and other previous documentation if available.

I think we are again back to "some documents being better than others" since, again, the BS7671-recommended ones do not seem to have any explicit place to record installation methods - so that information would not be recorded in such documents until the inspector found a way to 'volunteer' the information.

In the absence of that it's either a case of looking, or it's a limitation, which may lead to other problems.

Indeed, and ('problems' or not) is that not nearly always going to be the case? Since an inspector is unlikley to lift floorboards, and certainly won't deconstruct walls, other than for circuits which are visible in their entirety) in a roofspace (which must be very rare), an inspector will very rarely be able to tell, with any certainty, what method has been used for installation of the entirety of the cable of a circuit, won't they?

Kind Regards, John

 

[JohnW2]

Unfortunately that's not correct. You are not permitted to suggest remedial actions as part of the Report - the Report must instead simply be a factual statement as to what the identified issues are. Suggested remedial actions would need to be relegated to a cover letter or something - they cannot be within the Report.

I'm not really sure where that all comes from, since I don't think there are any 'rules' (other than those probably imposed by 'clubs' on their paying members) as to what physical form an EICR should take or what may not (or may) be recorded on it. I certainly see no such 'rules' in BS7671 - which, after all, is the 'inventor' of the EICR.

In any event, even within the constraints that you right above, there would often be ways of "identifying issues" which effectively indicated what remedial work was required - in the case of eric's example, something like "MCB rating greater than the 32A maximum for the cable it is protecting".