Testing

[tigerpaul]

I believe that you take ownership of the entire circuit when you add to it. Therefore you need to test the circuit as a whole.

If a lighting circuit for example has IR readings of 50meg ohms but all your new cabling tests out at >299 meg ohms, you still need to record the result as 50.

 

[EastAnglian]

Is this what you actually do? e.g. you have a "simple" 1 hour job to add a smoke detector to a lighting circuit in a large house, do you actually take out all the light bulbs, turn on all the light switches, disconnect the cables in the distribution board and carry out 3 insulation tests L-N, L-CPC, N-CPC on the whole circuit?

I don't!

 

[tigerpaul]

If you work on a circuit, don't you want to know it is safe and compliant?
And remains so after you've gone...

 

[jase]

BS7671 part 3 assesment of general characteristics
although it may well not be part 3 now as i havent got BGB yet :behead:

 

[EastAnglian]

If you work on a circuit, don't you want to know it is safe and compliant?
And remains so after you've gone...

Yes, but the question was about what you record on the certificate!

I agree, there is a professional obligation to satisfy yourself through pre-installation checks and other tests that the installation is safe. In the example I used above if I did have doubts I might carry out an IR test between L+N joined together and CPC but I would record this in my notebook or on the job sheet, not on the certificate.

 

[tigerpaul]

Yes but if you issue a certificate showing a circuits details and results, it should reflect the whole circuit, not just the "new bit"

 

[EastAnglian]

No, Regulation 633.1 is quite clear on that.

 

[jase]

yes it states that all of the conditions of SECTIONS 631 and 632 shall apply to all the work of the addition or alteration, so if you read 631.3 which is in SECTION 631 it says an MWC may be provided for each circuit altered or extended.

the CIRCUIT i.e the whole thing

it doesnt say you can just test the new bit and to hell wether or not you have just connected up to an unsafe installation!!!!

 

[EastAnglian]

yes it states that all of the conditions of SECTIONS 631 and 632 shall apply to all the work of the addition or alteration, so if you read 631.3 which is in SECTION 631 it says an MWC may be provided for each circuit altered or extended.

the CIRCUIT i.e the whole thing

it doesnt say you can just test the new bit and to hell wether or not you have just connected up to an unsafe installation!!!!

Interesting, and I understand the point you are making. However, using the same example, lets say I connect a smoke detector to a lamp on a lighting circuit, but not to the lamp at the end of the radial circuit. What do I measure to enter a value for R1+R2 on the MWC?