Ring Circuit R1+R2 readings

[kenny james]

i was always the one that use to ask the dumb question!, everybody would laugh when we left college i would be thanked by those who laughed who would say thats what they wanted to ask but was too afraid of asking!!.

 

[Grant Naylor]

@laws

This is an additional path to earth that has been introduced into the circuit. This maybe due to bonding of extraneous-conductive parts; or another example I suppose would be SWA that introduces parallel paths due to the earthing of the steel wire in addition to the CPC within the wire.

Essentially with parallel paths the CSA of the CPC is increased so the resistance would be lower that expected.

 

[SPARTYKUS]

Still a relatively inexperienced so sorry if these seem obvious/dumb questions.

When will people with little or no experience get the message. THERE ARE NO OBVIOUS, DUMB, SILLY OR STUPID QUESTIONS, so stop apologising!
We all learn't, we all asked. If you dont ask you wont find out. Just because some of us have been doing this all our lives doesn't mean we assume everyone else has. Your questions are certainly not dumb, they are relevant to what you are doing and learning. The answers to me are fairly obvious, thats because i have more than 30 years experience, you haven't, so to you the answers will not be obvious. NEVER BE AFRAID TO ASK, AND NEVER APOLOGISE FOR DOING SO.

Cheers............Howard

Howard

best post I have read for weeks.

Fine fellow.

 

[Rivo]

Whilst we are on the subject of R1+R2 readings, if I set my Megger multifunction tester on to Loop test, and plug it in to a socket, this reading will be my Zs.

Do I still have to mess around removing CPCs and Lines at the DB to get the R1+R2 readings or can I just N/A it on the PIR?

 

[malcolmsanford]

Whilst we are on the subject of R1+R2 readings, if I set my Megger multifunction tester on to Loop test, and plug it in to a socket, this reading will be my Zs.

Do I still have to mess around removing CPCs and Lines at the DB to get the R1+R2 readings or can I just N/A it on the PIR?

You don't have to mark not doing the R1 + R2 as anything, as you can easily do a R2 test on a PIR, as really on a PIR confirming continuity of protective conductors and your Zs is fine.

 

[SirKit Breaker]

I wont disagree with malcolm, he is correct. But what i will add is that i would always do the R1 + R2 by removing the conductors from the DB using the figure of 8 method and checking every outlet, this way you will identify spurs, spurs off spurs and any reverse polarity connections that DIY charlie has made, this will also show up any loose connections. I also repeat the same between L and N. I also always check r1, rn, and r2, because an EFLI test wont show up a broken ring final circuit.

To be honest carrying out a full test of the circuit doesn't take too long once you have done it a few times.

Cheers...........Howard