r1 + r2 testing

[bonio78]

hi, can any one help me to understand how the r1 r2 testing works please

 

[Guest123]

Hi.

Do you mean R1+R2 test or, the r1 and r2 tests??

 

[bonio78]

R1+R2 testing please

 

[tizbad]

[ame=http://www.amazon.co.uk/gp/offer-listing/185617607X/ref=sr_1_olp_1?ie=UTF8&s=gateway&qid=1246287242&sr=8-1]Amazon.co.uk: Used and New: Practical Guide to Inspection, Testing and Certification of Electrical Installations: Conforms to 17th Edition IEE Wiring Regulations (BS 7671:2008) and Part P of Building Regulations[/ame]

hi, this link should take you to christopher Kitcher, practical guide to inspection, testing and cert. of elec. instal. its to the 16th but i found it helpful when learning how to test.

sorry link doesn't work for some reason, just search for kitcher on ebay or amazon, worth the £ imo

 

[Guest123]

Hi.

If you are R1+R2 testing on a radial circuit then you simply isolate all power at the DB i.e main switch off, place a link between Line and Earth of the circuit you want to test, then go to the end of that circuit and measure the continuity between Line and Earth.

For a ring main again isolate, joint Line 1 to Earth 2, Line 2 to Earth one and measure at each socket on that ring circuit, the highest reading you get being recorded as the R1+R2 for that ring circuit.

Hope this helps.

 

[bonio78]

ok cheers, bare with me with this, on a radial circuit in a house, how would you know which is the last socket?
thanks for your help

 

[Guest123]

Hi.

Well I would switch all other circuits off apart from the one you want to test, then go round each socket with a martindale tester to see which ones were still live, i.e on that circuit. Chances are the furthest one away from the DB will be the last. It will also have just one T+E in it.

 

[tizbad]

the last socket will have one cable feeding it

 

[Mac]

Hi Lenny,what's the difference between R1+R2 and r1+r2 tests

 

[Guest123]

Hey bud.

People just get confused at times with the letters and symbols for things (or cant be bothered to use caps lock).

Little r1 is end to end continuity on the line conductor

Little r2 is end to end continuity on the CPC.

No such thing as r1+r2

It's R1+R2.

 

[scotsparky]

the caps lock button on the computer

testing R1 then R2 is testing continuity of each conductorseperatly
R1+R2 is testing both at same time.

hehe got there before me Lenny

 

[Guest123]

Always finish first....story of my life.

 

[Mac]

the caps lock button on the computer

testing R1 then R2 is testing continuity of each conductorseperatly
R1+R2 is testing both at same time.

hehe got there before me Lenny

Cheers mate

 

[scotsparky]

Lenny your misses tell you that mate????

 

[Guest123]

Used to, now we dont even bother.

 

[Richie Fox]

You know when you are at the last socket or outlet on a radial circuits as it will have the highest resitance reading and yes and single cable feeding it is a good indicator but beware as that may also be a radial off of a radial.

 

[ockey]

thanks 4 al yr help, im just leaningl,but u no what i ment ?????????? r1+r2 (R1+R2)

 

[ezzzekiel]

Hi.

Do you mean R1+R2 test or, the r1 and r2 tests??

pet hate of mine, but well explained my mr len

it can be difficult to accurately find last point in a circuit - as you move further down the circ the higher the reading , but more often than not you can guess which logical route to follow

 

[Monks]

I'm just bumping this thread as I have a similar question: Is there such a thing as an R2 reading? I've just been looking at one of the test sheets given out at college similar to the one that I will be using tomorrow in my Level 3 practical exam and it asks for an R2 reading as opposed to r2 (without caps). Is it just a typo, or am I missing something? Also, in the continuity part of the sheet next to it is a column for R1+R2 and a small column that says 'Ring'. I don't understand why the 'Ring' box is there; what is it asking for? There are no columns for r1, rn, or R1+RN.

Any help would be much appreciated. Thanks.

 

[Martin Bradley]

Good book to get for learners is Alan Lynch the part p Doctor.

 

[malcolmsanford]

R2 is Test method 2 it is used to find the continuity of both earthing and bonding conductors.

In the case of Main Equipotential bonding you would disconnect the, say water bond from your MET and croc clip it, then with at the pipe you would clip the pipe, as that is my way to ensure your BS 951 clamp is secure and do your reading, using a low resistance ohmeter

In the case of what your looking at on a distribution or final circuit, you would clip a wander lead onto you CU earth bar and at each point in the circuit you would take a reading of the CPC, with your low resistance ohmeter.The highest reading would be your R2 reading which you would put into that column. If this method is done then there is no need to do the R1+R2 test, though the majority of electricians prefer this test to the R2 one

The ring box is a tick. It would be checked off if the socket outlets in the installation was wired in a ring final circuit, if the sockets were wired in a radial then it is left unchecked.

 

[Monks]

Thanks for taking the time to write an in-depth response, Malcolm. Reading your reply has just jogged my memory and the continuity for the ring part of the sheet makes sense again now. I knew I was missing something as it made sense last week. Thanks again.

This forum is a fantastic resource. Cheers.

 

[tomma]

Little r1, rn, and r2 are end to end resistance measurements, of line, neutral and earth on a ring final circuit. Cross connecting r1 and r2 then taking a measurement of these in parallel, equals Big R1 + R2.

 

[telectrix]

ok cheers, bare with me with this, on a radial circuit in a house, how would you know which is the last socket?
thanks for your help

on a radial, the last socket is the one with only 1 cable in it.

 

[ezzzekiel]

On any circuit the last testing point is the one hidden in the smallest darkest place with mountains of rubbish on top

 

[martinh89]

Little r1, rn, and r2 are end to end resistance measurements, of line, neutral and earth on a ring final circuit. Cross connecting r1 and r2 then taking a measurement of these in parallel, equals Big R1 + R2.

from what ive been shown line end to end is R1, cpc end to end is R2 and neutral end to end is Rn.
The values of R1,R2 and Rn will indicate whether or not the conductors are continuous.
Once you cross connect the conductors to create a parallel circuit thats when they become r1 r2 rn

 

[tomma]

What you should have been shown is line end to end is r1, cpc end to end is r2 and neutral end to end is rn.
The values of r1,r2 and rn will indicate whether or not the conductors are continuous.
Once you cross connect the conductors to create a parallel circuit that's when they become R1+R2 This is documented on the initial Inspection and Testing report

 

[spencerwalters]

R1+R2 testing please

thanks for you information mate

 

[bf03yvd]

R1 is R2D2's pal.

 

[Pete999]

OP have not got a copy of the OSG? r1 r2 and rn, as well as R1+R2 is explained in some detail, as is the explanation in GN3

 

[trev]

And the award for ancient thread resurrection today goes to ........

 

[Geordie Spark]

And the award for ancient thread resurrection today goes to ........

It's just another KERCHING!!! moment.

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