A testing question for assessment.

[Goody]

Hi

We have to measure and record the highest r1+r2 reading for lighting & ring circuits respectively on the NIC but should we also show the assessor the measured r1+rn for all these outlets?

1. Should we measure r1+r2 at the switches as well as the light sockets?
2. On the ring is that OK to take Zs reading at the socket where the r1+r2 is the highest or should it be done for all the sockets?
3. I have a mirror light with a built-in plug for the shaver (SELV). What tests need doing on this and what the assessor will be after in regards to this.
4. When it comes to finding r1+r2 at low voltage spotlights (with transformers), is it OK to test it from where it branches out or should it be done at every spotlight.

Any feedback will be much appreciated.

 

[truckster]

Ready for arguements but I would say:

1. Yes, you need the max Zs which could be at a switch
2. If it's an EIC you have to do it at every socket but you only record the highest. It proves the cpc at each point.
3. A Zs at the final cpc connection
4 Again if its an EIC you will need to do it at every spotlight wherever there is a cpc, this obviously depends on how they are wired. I use the blue click plugs so I have a cpc at every light.

 

[Electricalserv]

The thing with testing at every point gets me....Yes it should be done by GN3 but if there is a reading at the furthest point in essense proves there is a CPC throughout the circuit anyway.

 

[Des 56]

Yes,but if you had a class 1 fitting

Who is to say that the continuous cpc is in fact connected at that fitting and also that the polarity is correct at that fitting

 

[Electricalserv]

Polarity would be proven at the last fitting anyway. You are testing live to earth. With live and earth joined at DB. If the polarity was wrong at a fitting before the last, it would read open.....

Metal fittings should all be inspected for earthing but inspection is different than testing....

 

[truckster]

Polarity would be proven at the last fitting anyway. You are testing live to earth. With live and earth joined at DB. If the polarity was wrong at a fitting before the last, it would read open.....

Metal fittings should all be inspected for earthing but inspection is different than testing....

How about this scenario? Two cpcs in a socket, sheathed together but not in the terminal, you would get continuity but that socket would be unearthed.

Or:
If the polarity was reversed in a socket you would still achieve polarity in the cables but the socket would deliver an incorrect polarity.

 

[Electricalserv]

How about this scenario? Two cpcs in a socket, sheathed together but not in the terminal, you would get continuity but that socket would be unearthed.

Or:
If the polarity was reversed in a socket you would still achieve polarity in the cables but the socket would deliver an incorrect polarity.

I am not saying you are wrong there but both of those situations would be found via inspection...not testing

 

[Goody]

Thanks, folks, for all the replies. I read somewhere that we don't need r1+rn readings for radials & light circuits - is that true? I don't want to be caught out for something that I was supposed to do but I didn't. That will be realy silly!

Cheers!

 

[Electricalserv]

Thanks, folks, for all the replies. I read somewhere that we don't need r1+rn readings for radials & light circuits - is that true? I don't want to be caught out for something that I was supposed to do but I didn't. That will be realy silly!

Cheers!

r1 & rn represent the live- live (end to end) and neutral - neutral (end to end) on ring circuits.

So no there is no r1 & rn on radials or lighting circuits.

 

[Goody]

Thanks, Electricalserv, but r1+r2 is read at the light sockets & switches by connecting L&E at the CU, likewise should we find out the values of r1+rn by joining L&N at the CU. Would the assessor query about this?

Thanks once again for the input.

 

[Sparky Ninja]

R1&R2 not r1&r2, get your terminology right. Assessors love pulling that up.

Is it an installation or a periodic?

 

[Goody]

R1&R2 not r1&r2, get your terminology right. Assessors love pulling that up.

Is it an installation or a periodic?

Thanks, widdler, for the caution and now this will stay in my mind forever. This is a CU change for my assessment.

Cheers!

 

[Sparky Ninja]

Thanks, widdler, for the caution and now this will stay in my mind forever. This is a CU change for my assessment.

Cheers!

If it's a consumer unit change then I would assume you are doing an installation certificate, therefore R1&RN on the radial circuits isn't necessary. However if any of the circuits are subject to overload, then you may want to do an assessment of the voltage drop, seing as you have changed (In) for the circuits, if this is the case then R1&RN would be required.

 

[Electricalserv]

R1&R2 not r1&r2, get your terminology right. Assessors love pulling that up.

Is it an installation or a periodic?

This mate. You must know your terminology....

 

[westham_872]

Have you checke dthe voltage leakage.