IR testing ?

[BES]

Hello all just reading Professional Electrician and noticed this on IR testing. Just wondered if anyone else was aware of this,came in with 17th in 2008. It slipped by me.:dunce2:

Live conductors and the protective conductor connected to the earthing arrangement. (Test 2)

Regulation 612.3.1 requires that the protective conductor has to be connected to Earth before the test is carried out. This requirement was introduced in the 17th Edition of BS 7671 in 2008. Prior to that time, it was acceptable to test between the live conductors and the protective conductor with the protective conductor disconnected from Earth. Often the cables were subsequently terminated without any further insulation resistance test being carried out. This is no longer acceptable.

However, insulation resistance testing between live conductors and the protective conductor, with the protective conductor disconnected from Earth, can be carried out during the installation process to ensure that the conductors have not been damaged during that process. It is good practice to carry out this test before part of the cable run is rendered inaccessible by, for example, partition walls being put into place.

Indeed, the sentence following Table 61 states that, ‘Table 61 shall be applied when verifying insulation resistance between non-earthed protective conductors and Earth.’

The lowest value obtained for Test 2 is recorded on the Schedule of Test Results as, ‘Live-E’.

Due to the vulnerability of electronic devices, which was mentioned above , it is acceptable to connect the live conductors together and measure between that point and the protective conductor when it is connected to the means of earthing, in accordance with Regulation 612.3.3.

 

[timbobelfast]

Yes, handy way of IR testing when disconnecting is not possible. All in Guidance Note 3 my friend.

 

[BES]

Timboblefast
The point i was making is the part where it says you cant remove cpc from earth bar when ir testing eg testing one circuit .

 

[Sparky Ninja]

It should be common knowledge really?

This is why the dead tests cannot be completed on an initial verification if the supply has not been introduced.

 

[BES]

Not to me widdler ive always ir tested with all circuit conductors removed then done relivent tests then done a global test if such as cu change . So if a new circuit was added you would leave l and n out and connect cpc to earth bar and test between ln le ne . Which result do you record on cert seperate circuits or the same global result for all circuits.