C2 Vs C3 for no RCD on various circuits

[n180]

So I'm getting various responses to this depending on how things are interpreted.

Here's a scenario:

Assume property is a tenanted property.

Assume cables are run buried in walls/under plaster (depth unknown).

Which of these circuits merit a C2 if they are not RCD protected.

1. Lights
2. Hob/oven
3. Smokes
4. Circuits with accessories/fittings in a bathroom.
5. Socket circuits with no access to outdoor use.

 

[pc1966]

Which of these circuits merit a C2 if they are not RCD protected.

1. Lights
2. Hob/oven
3. Smokes
4. Circuits with accessories/fittings in a bathroom.
5. Socket circuits with no access to outdoor use.

Take a look at the Best Practice Guide #4 (free online) as it has useful coverage on most things, but in general my interpretation is:

C1 = immediate danger to life (e.g. exposed live parts, incoming polarity wrong)
C2 = danger if single fault occurs (e.g. no RCD outdoors, as cable cut while gardening and contact with Earth likely)
C3 = improvement recommended (as unusual or multiple fault scenarios present danger that current regs mitigate)

In your list #4 is a clear danger, especially as the supplementary bonding which would have been done to meet previous regs is not always present or maintained over time as plumbers do stuff, etc.

While not in the guidance I think many folks would also be less forgiving of deficiencies in rented property as (a) the owner is making money off it, and (b) the owner is not personally exposed to the risks if they decide not to upgrade.

Finally, the BPG#4, etc, are guidance and you as the inspector has to look at the actual situation to decide how serious the risks are. You can imagine situations where multiple C3s make for an overall unsatisfactory situation, or something like lack of RCD on indoor sockets are a C2 danger based on how you see the occupants using them, etc. For your own protection take photos if you can, and notes of what you saw that merited your decision in case it is queried later.

 

[littlespark]

Technically all are C3. Overall satisfactory outcome. Make sure all are listed under the observations though.

However, being a rented property, the landlord should be encouraged to make things as safe as possible.
Strongly worded footnote, highly recommend upgrade to consumer unit…etc etc

Send a quote to upgrade in with the report.

 

[n180]

Thanks for the excellent responses.

 

[Dustydazzler]

This is the whole 'RETROSPECTIVE' thingy...

IF the circuits were all installed and have remained completely untouched prior to the 17th Ed then it can deemed they meet the Regs of that Era and Code 3 will suffice. You can not Code 2 somethings retrospectively as it was deemed compliant at the time of installation.

However if you have any way of reaching an extension lead from a socket Via a window or back door then I would be inclined to C2 it anyway

 

[Risteard]

I would say the bathroom scenario depends on whether there is correctly installed supplementary equipotential bonding or not.

 

[n180]

I would say the bathroom scenario depends on whether there is correctly installed supplementary equipotential bonding or not.

Good point.

For this scenario, no supplementary bonding.

 

[n180]

What about the point about not knowing depth of cables. Less than 50mm?

 

[davesparks]

You can not Code 2 somethings retrospectively as it was deemed compliant at the time of installation.

Yes you can, if it is now considered potentially dangerous then it is a C2 regardless of when it was installed.

There is nothing in the regulations to say that you cannot code something a C2 if it complied at the time of installation.

 

[loz2754]

What about the point about not knowing depth of cables. Less than 50mm?

Usually this is easy enough to see if you take off a socket or a switch.

 

[n180]

That's true, however in most cases what you can see of the cable is less than 50mm depth.

What I'm asking I guess is, all the circuits 1 to 5 I mentioned above, can in general constitute c3 because it met previous regs, however what if:

A. You know or can see it's less than 50mm or
B. You don't know the depth, is a LIM on the depth enough to justify a c3 or would an rcd now be a requirement?

 

[Risteard]

can in general constitute c3 because it met previous regs

Forget whether it complied with previous Regulations or not. It really has no relevance as to its safety given our current (excuse the pun) understanding of this. Instead just consider it on the basis of what safety deficit a non-compliance poses, and how serious that is.

 

[davesparks]

can in general constitute c3 because it met previous regs, however what if:

No, it is C3 because it is not a potential danger, it is something which could be improved for safety. It is additional protection only.

B. You don't know the depth, is a LIM on the depth enough to justify a c3 or would an rcd now be a requirement?

If you have an agreed limitation to the inspection then that is something that you do not inspect or test, you don't give it any 'C' code, you just record LIM against that item to indicate that it was a limitation on the inspection.




If an RCD is required for additional protection but is not fitted then it will generally be a C3, the protection it gives is additional to the primary protection.

If the RCD requirement is not for additional protection but is as a part of the primary form of protection (fault protection for example) then it would be a C2 for it not being fitted.

 

[littlespark]

Presumable no SPD, plastic CU, so another couple C3’s there.

If there’s no bonding, then it didn’t comply in the first place, so that would be a C2. Can’t have EEBADS without the EEB.

Everything can be solved by replacing the board to all RCBO of course, so a cover letter with the report, a quote as mentioned by me earlier, and hope they think it’s a job that must be done.

 

[cliffed]

Good point.

For this scenario, no supplementary bonding.

C2 then with no supplementary….ok if Rcbo protected