Quick question! - polarity

[mljc71]

Hi all,
Just require a little clarification on polarity, may be an easy answer but i'm still learnig!

I was doing my 2330 303 fault finding exam, i got to the ring final for continuity, I tested little r1 r2 and rn, found there was no continuity on the cpc, noted it as a c2 and stated further investigation was required.
Main question is could i have still tested or polarity? I was thinking (alot of that as we really havent had alot of practical sessions this year!) if i done fig 8 test ith R1 and RN and used the plug adaptor for the low resistance ohmeter and flicked the switches- would this prove polarity?

Thinking somemore..... if the sockets where DP would it still confirm polarity?

thanks in advance MLJC

 

[telectrix]

you would not be able to confirm polarity unless you used a wander lead. L at CU to L at accessories.

 

[Doug]

I presume you mean that the CPC was an incomplete ring and therefore only one of the two CPCs coming into the socket was connected back to the main earth terminal. You still had an earth connection at the socket and so you could still measure R1+R2 and Zs, but treating the CPC as a radial. These readings would increase as you move around the circuit away from the CU. Had it been a complete ring these readings should have been fairly similar around the ring.

When you measured R1+Rn you checked the integrity of the circuit but would not have known if L & N were reversed behind the socket.