c2 or is it

[Farmelectrics]

Quoting for some work following a recent eicr question looks like in a couple of occasions that they have spared of the 2.5mm ring with 4mm cable half a dozen times it has been coded a c2. There maintenance guy has said this isn't a fault as the 4mm cable is ok on a 32amp breaker what's your thoughts code or no code i have suggested we install it back on the ring and that I'm quoting from the eicr. thoughts please.

 

[Julie.]

Not sure I quite understand.

so 2.5mm^2 ring - then single (single or double socket outlets) fed off at various points on the ring forming single point radials?

So no multiple sockets (socket to another socket etc) off any one point of the ring?

if that's the case in general it could all be done in 2.5mm^2 no need to be 4mm^2 at all and nothing wrong with it.

Why has it been coded a C2 - what's the regulation breach that they associated with it on the EICR?

 

[buzzlightyear]

No code at all considing the 4mm of a ring on a 32 amp.

 

[Rockingit]

Smacks of code 'rip the customer off for unnecessary work', to me. Either that or the apprentice did the test on a Friday afternoon.

Absolutely nothing wrong at all with what you describe.

 

[James18288]

How is a spur off a Ring final circuit wired in 4mm twin and earth a C2 observation? How is it likely to become dangerous? Has the tester inspector provided any reasoning?

An EICR is checking for compliance to BS7671, not coding because it’s unusual, or “I wouldn’t have done it that way”! In my opinion any coding needs to be backed up by at least one regulation from the wiring regs that it is breaching. Not just an opinion that it is wrong.

Is it due to the terminations of both 4mm stranded and 2.5mm solid conductors into the terminals of a BS1363 accessory? In which case I may tend to agree this MAY breach 526.2 among other regs.

4mm T&E in its self on a ring in my opinion doesn’t breach any regs. 433.1.204 states RFC must be wired in AT LEAST 2.5mm copper conductors with AT LEAST 20a Iz (except micc). So 4mm T&E complies.

Recently I have come across a fair amount of coding which are at best a bit weak and at worst blatant fishing for work. Coding such as “C2 requires metal fuse box upgrade - plastic dangerous”. “C2 kitchen light not waterproof”.

I’m not sure how others who have been asked to do remedial works overcome this. Most individuals I haves spoken to are not likely to get another full EICR? (As it’s likely just a paper exercise for their letting agency).

I have sometimes retested the circuit in question (As in my opinion any one who has done this won’t have tested properly). And then issue a minor works for the circuit stating test values and regulations as to why it is compliant with the regs. This way the customer can keep the MWC as they would if any actual remedial work had been carried out.

 

[Farmelectrics]

its a 2.5mm ring main spured off to 6 socket outlets using a 4mm t&e can only persume the guy thinks you cant spur of a spur so he has given it a c2. but the cable can take the load so not ideal but cant see what regulation. its broken
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its lazy testing in my eyes when they dont quote a regulation next to there coding.

 

[James]

so are you saying, there is one spur connection to the ring that feeds 6 sockets?
if so, its non compliant.

if there are 6 spurs off different parts of the ring feeding 1 socket each then it is compliant.

 

[westward10]

What is the installation method of the 4.0 cable.

 

[Farmelectrics]

yes it looks like they have spured off 1 socket 6 times using 4mm t&e
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westwald says method c on test sheet but not attended site yet. quoting from test sheet but will attend site to see properly later this week.

 

[Julie.]

its a 2.5mm ring main spured off to 6 socket outlets using a 4mm t&e can only persume the guy thinks you cant spur of a spur so he has given it a c2. but the cable can take the load so not ideal but cant see what regulation. its broken
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its lazy testing in my eyes when they dont quote a regulation next to there coding.

Well that is non compliant, it does go directly against the regs.

However, that doesn't mean it's a C2, as the 4mm^2 cable should be capable of 32A (subject to installation method) so non-compliant, but safe is C3 for me.

 

[westward10]

Guarantee it is in some kind of containment which will derate it.

 

[Farmelectrics]

thanks julie think i will press a head as first stated and quote to reinstall on ring main

 

[ChrisElectrical88]

Yeah non compliant, only one point to be spurred off each part of the ring as per FIG15A(Think that’s right, haven’t got regs to hand).

doesn’t take much to derate 4mm either like @westward10 has said

 

[Pretty Mouth]

Assuming ref method C for the 4mm...

Can anyone tell me what regulation this doesn't comply with?

 

[James18288]

Assuming ref method C for the 4mm...

Can anyone tell me what regulation this doesn't comply with?

I haven’t got my copy to hand, however, Although I don’t think it is explicitly written. I would argue that 433.1.204 and appx 15 state that the reason a 32a OCPD is allowed on a RFC is that it is unlikely that at any point on the Ring final is likely to exceed 20a.

By installing 6 x sockets connected to one point, and no further over current protection, it more that likely is going to be able to overload the 2.5mm on the shorter leg of the ring. So even if the 4mm is installed method C and rated to 32a, the 2.5mm could become the sticking point. Even if the ring was perfectly balanced with equal legs, is the spur fed from a BS1363 socket outlet - with terminals rated to 20a.

For me it’s a difficult one to code. I’m leaning towards a C2 insufficient/inadequate cable sizing. But would not argue to much if someone had coded C3. Fairly easy fix with a switched fused connection before The first socket either way.