EICR Certificate - Should Bathroom light not having RCD protection be C2 or C3?

I don't do EICRs, but looking at Layout 1 (electricalsafetyfirst.org.uk) best practice guide, if you haven't got a C2 for absence of supplementary bonding in the bathroom, then absence of RCD  protection should be a C3

AdamG: 
 

Hello,

Is anyone able to please clarify?  An electrician has just undertaken an inspection to allow an EICR to be issued.  They have stated there is a requirement to have RCD protection for the bathroom light (given it a code C2) and so they are quoting £600 to fit a new consumer unit.  I appreciate that if the house was being built today that it would need to comply with the 18th edition regs which came into force in Jan 2019 and hence would indeed need an RCD on the bathroom light but my house was built in 1956 although has a 16th edition CU with RCDs on socket circuits only but I thought this should be coded as a C3.  Any advice greatly appreciated.

Thanks

More than likely should be a C3 but even if it did need RCD protection a RCBO would be a cheaper option or move the lighting circuit to the RCD side. Was this the only C2 code?

It would be less expensive to replace the bathroom light with an all insulated Class 2 type. But we have reg. 701.411.3.3 to consider, which covers “circuits serving the location”.

Of course a new consumer unit complying with B.S. 7671 18th edition would afford greater safety overall.

Z.

Another of the fit a new CU at any costs EICR then! It should be a C3, but I suggest that an RCD in a box in the lighting circuit is the cheapest way to go, and it is just as “safe” as a new CU. Is there supplementary bonding present, because a bit of G/Y to the light and pipes might well be hidden from view and would need a meter check, which I expect he has not done. Will the new CU have AFDDs, RCBOs, Surge protection, and several spare ways? Is £600 the “going price”, because that sounds like nice work if you can get it?

Apologies, the link i posted earlier is not the latest guide, this is bpg4-1.pdf (electricalsafetyfirst.org.uk) 

The codings for absence of supplementary bonding and RCDs are the same, but there is an additional C3 for absence of RCD protection to lighting circuits which should have been recorded.

I agree with David the cheapest solution would be to add an RCD in a box to the lighting circuit near the consumer unit, provided the cable in between doesn't need RCD protection for other reasons, eg buried in wall <50mm etc

However, technically, regs 411.3.4 and 701.411.3.3 refer to circuits, and a circuit is defined as “an assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s)”, so all of the circuit past the MCB in this case. An RCBO, if available for the CU, would do the job nicely, but i doubt if anyone would code an RCD in a box in this situation.

Depending upon the actual brand of the existing consumer unit, you may be able to get a couple of RCBOs for the lighting circuits and swap out the MCB for them instead. This thread highlights the ifs whats and maybes of the wiring regs whereby all they render is confusion. It's a 16th ed box but it's fine. RCD in a box? Also fine. RCBOs to retrofit and gain protection for all of the circuit rather than just the bathroom? Fine too.

Suggesting that an exposed short cable to an RCD box itself needs RCD protection is beyond ridiculous OM. That is so far from the obvious intent of that regulation it is crazy. The busbar in the CU or the tails are equally likely (or more so) to be a “risk”, so the RCD right next to the meter seems to be the only permitted solution. The RCD for lighting circuits has two purposes, one the unlikely case of direct contact with a single conductor (in other words not protecting against fingers in the bulb socket), and the case of fire protection caused by whatever. Any kind of direct contact with a single conductor at a switch is pretty unlikely, but this might be aimed at the metal light switches that seem popular at the moment although most are either earthed or class 2.

I can think of a possible scenario where RCD in a box might not be a good idea.

homeowner gets occasional tripping from said RCD and fumbles in the dark to reset it. Decides to fit a light next to CU so its easier. Takes the feed from the input side of the RCD, either as a mistake or deliberately (so stays on when RCD tripped). If an RCBO had been fitted, all of the circuit would be protected

OlympusMons: 
 

I can think of a possible scenario where RCD in a box might not be a good idea.

homeowner gets occasional tripping from said RCD and fumbles in the dark to reset it. Decides to fit a light next to CU so its easier. Takes the feed from the input side of the RCD, either as a mistake or deliberately (so stays on when RCD tripped). If an RCBO had been fitted, all of the circuit would be protected

Yes, that could happen but is it any worse than any other non RCD protected light anywhere else in the house other than in the bathroom.

Returning to the O/P would an ELV light be acceptable ? with the transformer in the loft or other place out of reach of anyone in the bathroom.

Are there other things wrong that would also push for a new CU - we cannot see it, but is it rammed full and in poor state and overloaded and generally crying out to be re-done ?

If not, then as others have said to change it is a sledgehammer to crack a nut. If RCD cover really is needed, there are ways to add it to the lights without a full CU change, and in many situations, (the  all enclosed plastic light being the classic) the RCD is not doing a lot anyway.

Often a 16th edition board can be re-configured to that more or less of the internals is supplied by  the RCD without doing more than changing the bus-bar links inside. That may or may not be possible. A photo would help.

Stupidly, if the bathroom light was fed from a length of flex plugged into the socket  circuit, regs wise it would be OK, though this is the sort of thing usually left by cowboys.

Mike.