EICR question, OLD AC RCD- code 3 or no code?

[nicebutdim]

@Julie.

My thinking, the capacity of which is limited, is that potential for issue exists due to the way in which this protective device operates and the fact that one new appliance has the potential to change that operation.

I take the above points, but believe old wiring colours aren't a good comparison as they will have no impact on a householder who doesn't tinker with fixed wiring in their home. Replacement of an old or failed appliance doesn't generally require consultation. Given that a significant number of domestic EICRs are carried out for the sole reason of complying with rental legislation, I feel this adds another layer to the issue as no one can look around the property and assume risk on the basis of appliances present at time of inspection.

Similarly, the issue of premature collapse doesn't generally involve variables - risk exists or it does not and remedial work is quite simple.

Furthermore, most inspectors who carry out EICRs won't have any means of detecting DC leakage, much less any interest in attempting to do so.

What I have taken away from this discussion is that a number of opinions in favour of not coding type AC RCDs are based on customer reaction. While I understand that position, I don't consider customer sensibilities to be a factor of testing and inspecting. It's an interesting discussion about what, on the surface, appears to be a simple issue.

 

[HappyHippyDad]

Another way to look at this might be that if we do not code an item as C3 because it complied at the time of installation, we are taking away the client's choice to make a significant improvement to the safety of the installation. They would be unaware of the improvements made to the wiring regulations, and of changes that are happening in the world of technology that can both contribute to safety, but also to introduce new potential hazards (in this case the DC blinding of older RCDs).
Coding it C3 at least makes the client aware that an improvement to the safety of the installation is actually an option.

That's an interesting way of saying 'covering my arse'

 

[pirate]

C5, anyone?

 

[pc1966]

But that would be at the inspector's discretion?

Now that you raise this point, I can't help wondering if it is possible to issue a satisfactory report containing a C2?

I think the point is C2 is an immediate "unsatisfactory" due to a clearly identified danger following a single fault, whereas C3 are not that dangerous in themselves.

But if you found an installation where practically everything was so rubbish it merited C3 you might come to the conclusion that overall it is not to a satisfactory degree of safety.

 

[nicebutdim]

I think the point is C2 is an immediate "unsatisfactory" due to a clearly identified danger following a single fault, whereas C3 are not that dangerous in themselves.

But if you found an installation where practically everything was so rubbish it merited C3 you might come to the conclusion that overall it is not to a satisfactory degree of safety.

I read more on this last night and it makes perfect sense when viewed in black and white.

 

[brianmoooore]

My interpretation is that anything that is not to the current version of the regs merits at least a C3. Every reg change should hopefully be an improvement, so anything which hasn't incorporated that improvement should be coded 'improvement recommended'.
There are many things I've installed in complete compliance with the regs that a few months later would attract a C3 on an EICR.
The plastic cased CUs in all my properties except one is an example that comes to mind, and now the type AC RCDs in those CUs.

 

[timhoward]

I then said - in that instance how would you code a voltage operated ELCB- it complied with the regs at the time of the install and you can test it with an RCD tester and the test button works so....

Going back to this point...
In almost all cases I consider this a legitimate C2, as:
...the chances are there'll be a lower impedance fault path via any metal services than via the earth rod, and the VOELCB needs current to flow via the earth rod to operate
...it will do nothing at all about a human caught between live and real earth

So we are only one step away from live parts and no ADS unless the Ra is exceptionally good.
As they were removed for safety reasons about 37 years ago I doubt I'd get as far as coding it - I'd just replace it.

Have you ever got one to trip with an RCD tester btw? I'd assume it would need more than 30ma to do anything as it's basically a solenoid.

 

[brianmoooore]

It's been decades since I came across a VOELCB, but I changed them on sight back then, so it's definitely a C2 if I found one now. They are not residual current devices, so I believe C2 is entirely justified.
Might be entirely wrong, but I have a recollection that the voltage operated devices had a resistance of around 60 ohms, so about 1.8V on the earth wire to trip it off.

 

[timhoward]

Might be entirely wrong, but I have a recollection that the voltage operated devices had a resistance of around 60 ohms, so about 1.8V on the earth wire to trip it off.

Completely academic now, I know....one of my very old books says the requirement was based on the Ze, if 200 ohms then tripping at <=24v was required and if 500 ohms it had to trip at <=40v.
The 14th Edition says the correct test is a test voltage not exceeding 45v applied to N and E on the installation side and it must trip instantaneously.
It may be that manufacturers did a lot better than the minimum requirement though!

 

[cliffed]

C3 for me & in all case’s regarding now & then situations…it covers your opinion/competence & is a recommendation for improvement in so many “grey” areas the Regs present to us those situations