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.