Gomez Addams said:

It trips on the button

That doesn't depend on an earth connection in most, if not all, RCDs.

Gomez Addams said:

No justification was given for the C2. When asked he would not discuss it. He just stated it has to be below 200 ohms. 

I don't think there's a point in arguing this. In TT systems, Regulation 643.7.1 b) is used to verify effectiveness of automatic disconnection of supply (for protection against electric shock).

This first requires measurement of earth electrode resistance as per 643.7.1 b) (1). BS 7671 (Note to Table 41.5) and the relevant IET Guidance Notes all say that an earth electrode measurement exceeding 200 Ω indicates the earth electrode resistance is possibly not stable.

The next step of testing ADS in TT systems relying on RCDs, according to Regulation 643.7.1 b)(2), is to test the RCD. The guidance in IET Guidance Note 3 for RCD Test Method 1 (test between live conductor and cpc downstream of RCD) implies it may not be safe to conduct the test if the EFLI exceeds the maximum limits (in the case of earth electrode, that would imply check the earth electrode is stable before testing).

Therefore, it may be the case that the person carrying out the test considered it not safe to proceed with RCD tests. It would be a potential breach of health & safety legislation for them to proceed with the tests if they believed it was not safe to do so.

Perhaps there are two ways to proceed from here:

1. Carry out some work to reduce the earth electrode resistance (e.g. repair, replace, or supplement with a second electrode ... doesn't have to be a 'rod' but installing in accordance with BS 7430, at a suitable depth, is strongly recommended).
2. Get a second opinion.

You picked out it trips on the button. I also said it trips on RCD tests too, all of them, and in less than half the limit.

I didn't know until later when I spoke to my tenant that he had told her "he didn't have the right equipment with him to do all the tests". So what didn't he have? RCD tester?

Also, the reports say 25% of accessories sampled. Another of my tenants told me, he didn't see the electrician remove any fitting whilst he was there.

I have zero confidence in anything he has said or reported. I have been through these properties myself in minute detail. I have no doubts they are safe.

Gomez Addams said:

You picked out it trips on the button.

Because that makes no odds to testing for BS 7671 conformity, which requires two steps as I said:

1. Earth electrode test; and
2. Then, if safe to do so, RCD test.

Gomez Addams said:

I also said it trips on RCD tests too, all of them, and in less than half the limit.

I also said it may be considered unsafe to do that test, if the earth electrode test  (or a loop impedance test) is not satisfactory. The electrician has to abide by the Electricity at Work Regulations whilst at work ... that may or ,may not apply to yourself, and I'm not questioning that.

As far as BS 7671 is concerned, the electrician may have considered the verification for ADS failed at "step 1" and stopped there (which as I have said, may be difficult to argue with if one has no other knowledge of the installation, as is the situation for myself and other posters here).

I'm not sure why going round in circles will change anything ... BS 7671 has criteria in Regulation 643.7.1 b), which the electrician obviously considered are not met, and just pointing at "step 2" of the verification in Regulation 643.7.1 b) doesn't change the status of "step 1" of that Regulation (at least in the eyes of the original electrician).

Gomez Addams said:

I have no doubts they are safe.

Whilst I wouldn't want to contradict you, as you have knowledge of the installation, I am discussing the criteria in the Standard we are supposed to be inspecting and testing against?

Gomez Addams said:

I didn't know until later when I spoke to my tenant that he had told her "he didn't have the right equipment with him to do all the tests". So what didn't he have? RCD tester?

Also, the reports say 25% of accessories sampled. Another of my tenants told me, he didn't see the electrician remove any fitting whilst he was there.

I have zero confidence in anything he has said or reported.

I'm not sure there's enough to go on here for me to comment further, and of course you'd need to make your own decision on each of these things.

However, in your original post, you only questioned the RCD test ... you said you believed the criteria are met, but I think on that particular point, the electrician may have been following the criteria as stated in Regulation 643.7.1 for TT systems?

Gomez Addams said:

You picked out it trips on the button.

Because that makes no odds to testing for BS 7671 conformity, which requires two steps as I said:

1. Earth electrode test; and
2. Then, if safe to do so, RCD test.

Gomez Addams said:

I also said it trips on RCD tests too, all of them, and in less than half the limit.

I also said it may be considered unsafe to do that test, if the earth electrode test  (or a loop impedance test) is not satisfactory. The electrician has to abide by the Electricity at Work Regulations whilst at work ... that may or ,may not apply to yourself, and I'm not questioning that.

As far as BS 7671 is concerned, the electrician may have considered the verification for ADS failed at "step 1" and stopped there (which as I have said, may be difficult to argue with if one has no other knowledge of the installation, as is the situation for myself and other posters here).

I'm not sure why going round in circles will change anything ... BS 7671 has criteria in Regulation 643.7.1 b), which the electrician obviously considered are not met, and just pointing at "step 2" of the verification in Regulation 643.7.1 b) doesn't change the status of "step 1" of that Regulation (at least in the eyes of the original electrician).

Gomez Addams said:

I have no doubts they are safe.

Whilst I wouldn't want to contradict you, as you have knowledge of the installation, I am discussing the criteria in the Standard we are supposed to be inspecting and testing against?

Gomez Addams said:

I didn't know until later when I spoke to my tenant that he had told her "he didn't have the right equipment with him to do all the tests". So what didn't he have? RCD tester?

Also, the reports say 25% of accessories sampled. Another of my tenants told me, he didn't see the electrician remove any fitting whilst he was there.

I have zero confidence in anything he has said or reported.

I'm not sure there's enough to go on here for me to comment further, and of course you'd need to make your own decision on each of these things.

However, in your original post, you only questioned the RCD test ... you said you believed the criteria are met, but I think on that particular point, the electrician may have been following the criteria as stated in Regulation 643.7.1 for TT systems?