BS7671 524.1, C2 or C3

[Pretty Mouth]

OK I understand the cable capacity and I understand the fuse, correctly chosen. What I do not understand is how this complies with BS7671 without a written risk assessment, not provided by the installer, clearly this is a "departure from regs" situation at the very least.

Turn the page to P145. It says :

Non-sheathed and sheathed flexible cables - For a specific appliance - Copper - As specified in the product standard.

So whatever the manufacturer states as the minimum CSA, is fine.

 

[Tunni]

Thanks for the input folks. I think I will just add the observation of the CSA of the conductor to the cert and leave it at that.
I guess in some ways it's down to a perception of where a "power circuit" starts and ends. To my mind it is everything up to the point of the manufacturers' supplied equipment however I can see that as with everything EICR there are many ways to approach such things.
Not keen on 0.75mm flex though, regardless, in this kind of situation.

 

[suffolkspark]

Thanks for the input folks. I think I will just add the observation of the CSA of the conductor to the cert and leave it at that.
I guess in some ways it's down to a perception of where a "power circuit" starts and ends. To my mind it is everything up to the point of the manufacturers' supplied equipment however I can see that as with everything EICR there are many ways to approach such things.
Not keen on 0.75mm flex though, regardless, in this kind of situation.

Nooooo. You shouldn't even be noting it. It's perfectly compliant, please just stop ?

 

[Pretty Mouth]

May I be permitted to hijack this thread? Table 52.3 goes on to say:

Non-sheathed and sheathed flexible cables - For any other application - Copper - 0.75mm².

This appears to say that when flexible cable is used for any application (presumably that includes power circuits and lighting), a minimum 0.75mm can be used. What do you guys and girls make of that?

 

[Tunni]

so consider this. a FCU connected to a socket (power) circuit with a 5A fuse to feed a light/s in 1.0mm T/E. for example in a shed/garage siruation. would youcode that?

Come off it. This was a specific query. And I am grateful for the advice given. I remain unconvinced by the use of this particular flex however I am aware and have always been aware that electrically it is sound. My query regarded the application of a specific part of the regs and how people here would interpret that.

 

[loz2754]

My thoughts on the C2 were precisely that it would be a method by which the homeowner could apply leverage to get the plumber back to use a "better" cable. A C3 will most likely be ignored.
Recognising that in all fairness the installation is practically sound I guess a C2 is an overreaction perhaps. I still wonder about the fact that this is clearly a power circuit conductor, chosen by the installer and not compliant.

It's not our job to influence or leverage anybody, only to report what we find.

 

[Tunni]

May I be permitted to hijack this thread? Table 52.3 goes on to say:

Non-sheathed and sheathed flexible cables - For any other application - Copper - 0.75mm².

This appears to say that when flexible cable is used for any application (presumably that includes power circuits and lighting), a minimum 0.75mm can be used. What do you guys and girls make of that?

Fair enough that. It puts my query to bed properly. If the plumber is convinced then it's his shout. I will add the note but that is that.

 

[westward10]

I could understand this if the 0.75 was connected to an immersion and protected by a 13A fuse, I would Code this all day long but on a boiler with a 3A fuse it doesn't warrant any note in a Report.

 

[Strima]

The fixed wiring stops at the FCU.

The manufacturer has supplied the flex so has deemed it suitable for use.

Your job is to inspect and test to the current edition of BS7671 and report accordingly, not to influence.

No code or comment required if the flex is in good condition with no signs of deterioration or damage.

 

[Tunni]

Strima, thanks for your input. I was never certain where the fixed wiring was deemed to stop before. It is obvious enough where a manufacturer has supplied a flex or such but as with an earlier example here an fcu used to change from a ring or radial ( for example ) to a lighting circuit with different dimension cable is not a problem, except in that case the addition is subject to all the usual scrutiny of its type. I had rather foolishly not dug deep enough into the regs to unveil the nugget of info pointed out by Pretty Mouth (thanks), especially so as it was on the very next page. This puts my question to bed. Mea culpa!

 

[GBDamo]

Well that took a while.

 

[7029 dave]

Well that took a while.

Yeah 26 posts worth.

 

[EricMark]

Oh dear, what was happening hear, how could anyone consider even 0.5 mm² cable with a 3 amp fuse was potential dangerous?

I must admit there does seem to be a difference in some books and paperwork as to what is and appliance and what is an installation, I would have said cooker hoods, extractor fans, boilers, immersion heater, built in cookers and hobs etc were alliances, but it seems building regulations class them as installations as they are fixed to the building.

So if part of an EICR then we most inspect and test them, as with opening a plug if not moulded to check there is a clamp on the flex, you should also open up the appliance to ensure all cables are suitable clamped, however we are told the covers on a boiler are part of the gas tight structure and should only be removed by some one registered as gas safe, so it seems boilers are a special case.

However the EICR had code 4 dropped, it was dropped because there was a problem listing all the non compliance with latest editions, the problem was unless there is an installation certificate for an installations then no tester can know if the design was before or after a change in BS 7671 requirements, so the tester would have to test and inspect as if it was installed yesterday, the result was loads of unnecessary code 4 being raised, not sure if a agree with code 4 going, as I feel the owner needs to know before adding to a circuit for example a RCD will need fitting, but the IET seems to have felt loads and loads of code 4's was not help full so was dropped.

However nothing stopping you recommending fitting of an RCD so that circuits can be altered in the future without problems.

But essentially when we moved from code 1,2,3,4 to C1, C2, C3 then our remit changed and we report on the condition and safety of the installation not as to if it follows current or any other version of BS 7671, hence why professional indemnity insurance is required, your giving your opinion, not that of any publication. The books may guide you as to what is permitted, as lets face it, 230 volt is always potential dangerous, and our insurers may give conditions which could include must comply was a set of rules they feel appropriate. But latest edition of BS 7671 does not really help when the latest edition always starts with the dates to which it covers designs from, so a house where wiring designed in 1965 still does not need an earth to light fittings, or any RCD, if following the wiring regulations, will not say BS 7671 as it did not exist back then.

In this case of course covered by latest edition, however since EICR is not any longer tied to any edition since dropping of code 4, then your looking at danger not if it complies.

So for example if I inspect a property with a type AC 100 mA RCD and a TT supply, and a electric car charging point has been added even a 16 amp one, then does it fail, even with all 30 mA does it fail? As the RCD may not trip due to a fault with the car charging. But hang on back in 1954 when house built and the installation was designed we did not have a RCD, but in 1954 with did not have so many electrical goods, my dad told me how proud he was of the electrics of his new house, as it had 5 sockets, my grand fathers house only had 2. And in my great grand fathers day plugging the smoothing iron into lights was illegal as lights was on a different meter to sockets and you paid less for electric from lights meter. Grandma always plugged iron into lights, there were no sockets in the kitchen.

When the MOT came out, we had a book, and it said what the tolerances were, and I remember a dial gauge on a wagon wheel to measure king pin play, if allowed 1/8" that was limit, never mind if safe or not, but if it was not safe, the Dot could still stop you on way home from test station and issue a GV9, even if it did pass the MOT.

So in theory with a new install some one can follow BS 7671 to the letter, and then some one can come and do an EICR and issue a code 2, as they feel it is potential dangerous even if it follows BS 7671. The reverse is also true, an EICR is not anything to do with BS 7671 it is a personal assessment, OK we are guided by many publications as to what we pass or fail but we are not tied to BS 7671 although we may be tied to what our insurers say.

 

[loz2754]

Oh dear, what was happening hear, how could anyone consider even 0.5 mm² cable with a 3 amp fuse was potential dangerous?

I must admit there does seem to be a difference in some books and paperwork as to what is and appliance and what is an installation, I would have said cooker hoods, extractor fans, boilers, immersion heater, built in cookers and hobs etc were alliances, but it seems building regulations class them as installations as they are fixed to the building.

So if part of an EICR then we most inspect and test them, as with opening a plug if not moulded to check there is a clamp on the flex, you should also open up the appliance to ensure all cables are suitable clamped, however we are told the covers on a boiler are part of the gas tight structure and should only be removed by some one registered as gas safe, so it seems boilers are a special case.

However the EICR had code 4 dropped, it was dropped because there was a problem listing all the non compliance with latest editions, the problem was unless there is an installation certificate for an installations then no tester can know if the design was before or after a change in BS 7671 requirements, so the tester would have to test and inspect as if it was installed yesterday, the result was loads of unnecessary code 4 being raised, not sure if a agree with code 4 going, as I feel the owner needs to know before adding to a circuit for example a RCD will need fitting, but the IET seems to have felt loads and loads of code 4's was not help full so was dropped.

However nothing stopping you recommending fitting of an RCD so that circuits can be altered in the future without problems.

But essentially when we moved from code 1,2,3,4 to C1, C2, C3 then our remit changed and we report on the condition and safety of the installation not as to if it follows current or any other version of BS 7671, hence why professional indemnity insurance is required, your giving your opinion, not that of any publication. The books may guide you as to what is permitted, as lets face it, 230 volt is always potential dangerous, and our insurers may give conditions which could include must comply was a set of rules they feel appropriate. But latest edition of BS 7671 does not really help when the latest edition always starts with the dates to which it covers designs from, so a house where wiring designed in 1965 still does not need an earth to light fittings, or any RCD, if following the wiring regulations, will not say BS 7671 as it did not exist back then.

In this case of course covered by latest edition, however since EICR is not any longer tied to any edition since dropping of code 4, then your looking at danger not if it complies.

So for example if I inspect a property with a type AC 100 mA RCD and a TT supply, and a electric car charging point has been added even a 16 amp one, then does it fail, even with all 30 mA does it fail? As the RCD may not trip due to a fault with the car charging. But hang on back in 1954 when house built and the installation was designed we did not have a RCD, but in 1954 with did not have so many electrical goods, my dad told me how proud he was of the electrics of his new house, as it had 5 sockets, my grand fathers house only had 2. And in my great grand fathers day plugging the smoothing iron into lights was illegal as lights was on a different meter to sockets and you paid less for electric from lights meter. Grandma always plugged iron into lights, there were no sockets in the kitchen.

When the MOT came out, we had a book, and it said what the tolerances were, and I remember a dial gauge on a wagon wheel to measure king pin play, if allowed 1/8" that was limit, never mind if safe or not, but if it was not safe, the Dot could still stop you on way home from test station and issue a GV9, even if it did pass the MOT.

So in theory with a new install some one can follow BS 7671 to the letter, and then some one can come and do an EICR and issue a code 2, as they feel it is potential dangerous even if it follows BS 7671. The reverse is also true, an EICR is not anything to do with BS 7671 it is a personal assessment, OK we are guided by many publications as to what we pass or fail but we are not tied to BS 7671 although we may be tied to what our insurers say.

When I conduct an inspection and test it is always to the current edition of the latest standard, BS7671. There will be things that do not comply to the current edition but may still be considered safe for continued use. This is where the experience and judgment come in. It is up to me as the inspector to decide on what code, if any, to apply to any such non compliances. In some cases I don't put a code but still make a comment so the person ordering the report is at least aware. In other cases, I use my experience and judgment to decide between a C2, C3 or FI.
I use whatever guidance I can find if there is something I'm not sure of. But always, in every case, the standard I am using to judge each case is the current edition of BS7671.

 

[Rockingit]

OK we are guided by many publications as to what we pass or fail but we are not tied to BS 7671 although we may be tied to what our insurers say.

Your insurer's will say the same as every other body - adhere to BS7671 and you'll most likely be fine.