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Little scenario for you all.

I've been doing an eicr today and come across a double socket wired as a radial on a 2.5mm t-e, which is protected by a 32 amp rcbo.
Technically this cannot overload as the cable can withstand 27 amp ref method c. Unless mr DIY comes along and starts adding new sockets which I am not responsible for so my question is would you leave it
 
IF overload and thermal constraint limitations are met, it complies with BS7671 so no code, no comment

I think there's a danger of confusing "Is this an absolute top-notch covered-all-the-bases, cable-cannot-be-rogered-by-incompetent-additions-or-rogue-equipment design?" with "Does it actually require improvement and if so on what grounds, preferably supported by the regs?"
 
I think there's a danger of confusing "Is this an absolute top-notch covered-all-the-bases, cable-cannot-be-rogered-by-incompetent-additions-or-rogue-equipment design?" with "Does it actually require improvement and if so on what grounds, preferably supported by the regs?"

Then again we are told to flag up "Some circuits which require RCD protection under the current regs have none" as a C3...does that require​ improvement?...my brain hurts.
 
Exactly, so therefor you have to create a circuit to prevent this, IMO it's down to good workmanship and pride in your work.!!

No, you don't, where do you want to stop babysitting the stupid who abuse an electrical system? Let's pull the main fuse in case somebody abuses the tails to the board and decides to splice a light for his shed into it.

I take huge pride in my work, like I said before I would not go out of my way to do something like this. But! If I saw a busbar chamber and 2.5mm straight from the busbar to a double socket below I would not code it on a EICR. The 2.5mm CANNOT be overloaded!
 
The cable would be protected against overload - IF

It only served one piece of equipment at the end of it's run and nothing on the way, so you can't have a radial with 3 double sockets on it obviously.

Obviously you can't have a 16A socket at the end because these have no fuse system, but you could have one 13A socket or one switch fuse (fused appropriately for the cable)


I am not saying I go out of my way to install like this, I use an appropriate sized MCB at the origin like anyone else, but technically you don't have to.

Do you think you can't have a 16 a socket outlet on a 32a mcb ?
 
Having reminded myself that a C3 means improvement required, I now agree, no code is appropriate. I would say maybe a comment but I don't think the EICR form lends itself well to comments that aren't tied to codes (observations section requires a code for any observation made). Amazing what you can learn from civilised discussion. Cheers.
does it now...


hopeless....
 
I certainly wouldn't advocate the scenario, and have always worked on the basis of MCB egual or less than CCC of cable. I have always replaced 'offending' MCB's in the past with something more 'suitable' but maybe I've been over cautious? I don't get involved with EICR's so don't have the dilemma of which code is 'appropriate' :)

Haha, you're gonna have fun trying to bend those 95mm conductors off a 200A busbar into a 32A switch fuse one day :D

As for the rest of the thread, anyone who would consider coding something that is perfectly compliant with current regulations has no business conducting EICRs IMHO. Note it by all means but you cannot code it.

Just today I was stood at my trade counter, I was being served whilst listening to two chumps on the other side talking about EICRs, one of them I know for a fact is a five week whizz kid. One of them (the other one) noticed my apprentice sniggering right about the point when a C1 for no bonding was mentioned, he looks over at my guy and just before the melt opens his mouth I cut in with "So you'd C1 lack of main bonding would you?" He doesn't seem too happy with the challenge but promptly and sneerily answers with "Of course I would, wouldn't you?!" There's about 10 or so guys standing near the trade counter and all is silent at this point. I say to him that anyone C1ing lack of bonding has no business carrying out EICRs. Out the corner of my eye I can see a few others raising their eyebrows whilst a couple more are grinning. Perfect timing as my stuff gets dumped on the counter and as I'm picking it up and heading on out of the door I turn to the fella and suggest that he invest some of his time in completing an electrical qualification. He doesn't even reply, he just looks down at the floor. Priceless!

Back to the topic in hand though, there are some codes that are subjective, but for the vast majority of them there is no argument. A compliant install is a compliant install.
 
The original OP was about an EICR code for a twins socket installed with 2.4mm backed up by a 32a cb, correct? Appendix 15 page 425 Figures 15A and 15B lays out the parameters to abide by when installing BS 1363 switched socket outlets, in 3 differing scenarios.
1/ Ring Final Circuit wired in 2.5mm
2/ 20amp radial wired in 2.5mm
3/ 32amp radial wired in 4.0mm

Someone mentioned, I can't remember who it was that if we read the Regs then there are different ways of installing these circuits, I'm not saying that there isn't but if whoever said this can point me in the right direction (within the Regs) then I may change my mind, but until that happens, Appendix 15 is my guide.
 
the OP's scenario is notthing to do with app. 15. it's a 2.5mm radial on it's own 32a RCBO. while theoretically, the cable can't be overloaded as it feeds a single point of use ( twin S/O , max. load 26A ), we have a situation where In>Iz. ( 433.1.1 (ii)). that's why i'd recommend reducing the OCPD value.
 
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What's the socket being used for?
Is there any reason for it to be on a 32A RCBO other than the argument that it's not technically against the regs, or alternatively any reason why it can't be on a 20A RCBO in accordance with the OSG other than the cost of changing it?
 
The original OP was about an EICR code for a twins socket installed with 2.4mm backed up by a 32a cb, correct? Appendix 15 page 425 Figures 15A and 15B lays out the parameters to abide by when installing BS 1363 switched socket outlets, in 3 differing scenarios.
1/ Ring Final Circuit wired in 2.5mm
2/ 20amp radial wired in 2.5mm
3/ 32amp radial wired in 4.0mm

Someone mentioned, I can't remember who it was that if we read the Regs then there are different ways of installing these circuits, I'm not saying that there isn't but if whoever said this can point me in the right direction (within the Regs) then I may change my mind, but until that happens, Appendix 15 is my guide.

This refers to numerous socket outlets on a radial so of course the 20A OCPD is appropriate (overload protection)
 
Back to the topic in hand though, there are some codes that are subjective, but for the vast majority of them there is no argument. A compliant install is a compliant install.

Would you agree though that a compliant install can still merit recommendations for improvement? For example, a 32A type B 60898 cooker radial showing 0.25ohms Zs at the cooker connection point but a barely-passing persistent 1.1ohms at the socket outlet on the cooker isolator?
 
What's the socket being used for?
Is there any reason for it to be on a 32A RCBO other than the argument that it's not technically against the regs, or alternatively any reason why it can't be on a 20A RCBO in accordance with the OSG other than the cost of changing it?

The main question has been how you would code it for an EICR, I believe most who are installing it would protect it with 20A OCPD (diversity etc), but technically you don't have to.
 
Is there any reason for it to be on a 32A RCBO
Yes, fault protection.

other than the argument that it's not technically against the regs,
It is not 'technically' anything - it is compliant.

or alternatively any reason why it can't be on a 20A RCBO
No.

in accordance with the OSG other than the cost of changing it?
Ah. that sums it up.

The OSG is 'one size fits all' without having to think or do any sums.

The OSG is smaller than the BGB so obviously does not contain everything.
 
Yes, fault protection.


It is not 'technically' anything - it is compliant.


No.


Ah. that sums it up.

The OSG is 'one size fits all' without having to think or do any sums.

The OSG is smaller than the BGB so obviously does not contain everything.


Possibly Yes if expected load may exceed 20A

Geoffsd - daft question but - how do you individually quote sentences (as in your post)?
 
Would you agree though that a compliant install can still merit recommendations for improvement? For example, a 32A type B 60898 cooker radial showing 0.25ohms Zs at the cooker connection point but a barely-passing persistent 1.1ohms at the socket outlet on the cooker isolator?

C3 - Non-compliant with 134.1.4
 
Yes, fault protection.
I was questioning the 32A bit more than the RCBO bit - if the maximum the plugtop fuses will allow you to draw is 26A why would you 'need' a 32A OCPD, especially considering the maximum current rating of the cable is 27A?
It is not 'technically' anything - it is compliant.
This seems to be the argument - does one cable coming out of the RCBO make it a radial, or is it 'just the same as' spurring off a 32A ring final, even though it isn't the same because there isn't a ring final there?
With a 2.5mm ring you might want a 32A OCPD to avoid 'nuisance tripping' due to a larger number of sockets, but in what kind of situation would you need to be able to draw anything near 20A from one double socket? If there is a reason for needing so much current I would expect there to be a need for more sockets, which would invalidate the argument that it's 'just the same as' spurring off a 32A ring.



The OSG is 'one size fits all' without having to think or do any sums.

The OSG is smaller than the BGB so obviously does not contain everything.
This sounds like installing something not because you need it but because you've found some loophole in the regs and using it as an argument for it being 'allowed'; IMO the question should be 'why would you'?
I can't picture what it is but there might have been a good reason for doing this; on the other hand someone might have done it because as far as they knew sockets go on a 32A OCPD, in which case it should probably be changed for a 20A to avoid unnecessary confusion.
 
To throw another one in,what was the socket used for? maybe he had a welder on it if originally on a 16 or 20 amp breaker then instead of changing it for a type C he just upped the breaker to a 32A,strange but I,ve seen it done.in fact I recently had a neighbour ask if I had a 32 that he could swap as he'd used the old immersion circuit to power his welder from,every so often it would trip the breaker but not take out the 13A fuse in the plug top.I pointed out that he should leave it as a 16A but consider a type C instead of a B subject to the earth loop values of course.
 

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