Can you replace just the RCD, instead of whole consumer unit?

If that is the same part number, there is no reason why it cannot be replaced. It would not bring the installation up to the current standard, but assuming that all else is good, it would be satisfactory.


There are some oddities in that report!

As described it seems an odd recommendation. Without knowing more about the inspector and what exactly was done, if the only problem was that RCD does not trip off when it should, then changing it would be cost effective and sensible, if the spare part is still available.


If there are other issues with the unit, such as mechanical damage or evidence of overloading etc, that would be a different matter.

Be aware that makers often have more than one pattern of RCD over the years and the new ones may not fit a board over a certain age, so do check the part numbers carefully. (and mixing devices of more than one make brings folk out in a rash of liability related panic, some are interchangeable, but others are not, even if they look similar, they may not make good contact to the bus bar etc.)



Also that table of results looks quite incomplete -

Firstly all the insulation readings are the same, so I presume it was all tested at once, which Is Ok, as it is well above the pass/ fail limit, but how one performs a figure of 8 test on a radial circuit is a bit of a mystery, as is the declaration of  R2 or R1 + R2 as "LIM"  for most circuits, meaning that the earthing of the cooker, the oven, the lights and the radial sockets have not been verified. In fact only the two rings seem to have been verified as earthed at all. How many man hours did you get for your money and was access to parts of the building blocked ?

Are there really so many circuits that are unknown, or are they really 'not used'  and blanked off. ?


More info needed I think.

Mike.

Bear in mind that busbar arrangements are not standardised, and vary between manufacturers - and more importantly, the same manufacturer may change over time. In particular, the depth of the busbar varies (i.e. looking into the CU, how near or far away it is) and the shape of the busbar prongs - may be fingers or twin fingers, or solid - just slight notches cut in the busbar. So a current device may not mechanically fit in an older CU.


Is this RCD acting as the main switch?

There must have been several man hours, what with all the disconnection of all loads and the time to reconnect them again.


There is that flying pig again. Always sets the alarm bells ringing.

Some of the testing looks a bit, er, 'brief' (no Zs or R2 for the non-RCD circuits, test button on the RCD "N/A" and no attempt to insulation test at 500V even when the 250V test showed 'clear'?) - I do wonder if enough has been done to correctly establish that it is the RCD itself that's the problem - and not for instance a N-PE fault either within the fixed installation or in an appliance that might have been in-circuit during the "test" of the RCD, or just some connected appliance holding the voltage up for a fraction of a second - depending on the nature of the fail.

   - Andy.

The RCD is separate to the main switch, I now have photographs.  I was mistaken in the RCD type, it is infact an MK Sentry 5760s.

I have spoken with another electrician to get a second opinion, he said that the test results seem strange, as the trip responded in 30ms above 30mA as it should, but marked faulty because it didn't trip below 30mA but electrician 2 seems to think that's by design and shouldn't trip with currents lower than 30mA.

The EICR test cost was £99, and was booked through MyConstructor who seemed to have good reviews, they seem to act like an 'Uber' for electricians and pool out the job.  He spent around 90 minutes in my apartment and had access to all fittings and fixtures.