Lighting testing

[doodarr]

Hi guys,

Quick question. I had a young lad (going to do his part P) with me yesturday coming along for some hands on (watching new install, wiring sockets, nothing live and a bit testing).
When testing the continuity of CPC the reading was something like 0.41. The kid was adimant that it had to be below 0.05?!?! Wouldnt have it that it could be higher. Only thing I can think of is he's getting confused with bonding. Am I missing something totally obvious that he can be getting mixed up with? Any references off top of your head would be great (save me putting head in books lol)

 

[telectrix]

the 0.05 is the max. reading you should get between extraneous parts that are bonded

 

[doodarr]

Sorry I was writing that quickly on my phone. The circuit I was testing was lighting in the loft not bonding.
I can't think of any other reason he would think that.

 

[doodarr]

Possibly the 0.05 ohm paramiters for Ring testing to differ by?? Just voicing out ideas now

 

[telectrix]

estimate the length and calculate what the resistance should be from tables in 0sg. then show him that.

 

[tony mc]

It would have to be a very short lighting cct to attain 0.05 ohms especially if you CPC is 1mm csa with a mohms/m of 18.10 ! Around about 2.5 meters in length that lighting cct. I will go with post 2 !

 

[tony mc]

Get him to have a good read of GN3 that will answer all your testing questions !

 

[doodarr]

I'm not giving him my books lol. He'll get them all on the course or before I would hope. He was adimant I was wrong lol. I thought 0.41 wasn't bad at all lol

 

[DaveyD]

Agree. Tel's first reply is what he is thinking of.

 

[doodarr]

Hey guy's,

It was bonding he was refereing to which was the only thing I could think of and was suggested by you all to.

Thanks for your quick replies.