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  1. haptism
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    haptism Regular EF Member

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    SW. London
    Hi for a ring circuit, is there any need to measure and enter R1 + R2 values on a schedule of results ? Because an r2 value is already measured (together with r1 and rn). If I needed a ring R1 + R2 value to calculate ZS (although i would find ZS with a socket tester so really no need; but if I did) would i find it using the formula ZS = (r1 + r2)/4 ? Thanks all
     
  2. Hellmooth
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    Hellmooth Electrician's Arms

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    Verification that it is a ring circuit would be a good reason.
     
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  3. jackhammerJIM
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    jackhammerJIM Regular EF Member

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    north yorks
    That would be r1 rn r2 . not R1 + R2

    R1 + R2 IS required to confirm polarity
     
  4. Wilko
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    Wilko Electrician's Arms

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    Berkshire
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    Yep, values from testing are needed for your test schedule for both r and R. GN3 has method laid out in section 2.2.6.
     
  5. haptism
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    haptism Regular EF Member

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    SW. London
    I dont have GN3 yet unfortunately. On the test schedule (IEE model form) there is a column for r1, r2, and rn values, so its obviously a ring im testing. The next column along asks for either R1 + R2, or R2; R2 is long lead method which would give exactly the same value as r2. So with that in mind whats the point of recording an R1 + R2, or R2 value if you have already measured r2 ?? Which my question is, do I need to enter an R1 + R2 value if i already have r2 ?? If you get what I mean that would be great ;)
     
  6. jackhammerJIM
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    jackhammerJIM Regular EF Member

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    north yorks
    yes you need R1 +R2 to confirm polarity
     
  7. telectrix
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    telectrix Scouser and Proud of It Trusted Advisor

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    R2 reading wound not be same as r2.
     
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  8. Wilko
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    Wilko Electrician's Arms

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    Berkshire
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    Def recommend GN3 ... I do tests and enter values for r1, rn, r2 and (R1+R2). Then I compare (r1+r2) to (R1+R2), looking for the magic 4 factor if I've built it right :)
     
    Last edited: Jan 11, 2017
  9. kropaske
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    kropaske Active EF Member

    Location:
    Feltham
    With r1 r2 rn you confirm that it is RFC by doing R1+R2 you verifying that cpc is actually connected to the socket and as jackhammer said verifying polarity
     
  10. sparksburnout
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    sparksburnout Electrician's Arms

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    Notts
    Or an I&T course? Like a sparks....
     
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  11. Risteard
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    Risteard Electrician's Arms

    Location:
    Derry, Ireland
    Business Name:
    Walsh Electrical Services
    It certainly shouldn't if done correctly! In fact it should be a quarter of the r2 value if there are no spurs. But given that the test for the (R1+R2) value is required as part of the ring final circuit continuity tests I see no merit in opting for R2 over (R1+R2) presuming that we are discussing initial verification here.
     
  12. haptism
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    haptism Regular EF Member

    Location:
    SW. London
    Okay, so in step 3 of the ring final test, when you cross connect L + E, the highest result is your R1 +R2. Having a brain drain today, quickly why would R2 differ from r2 ?
     
  13. kropaske
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    kropaske Active EF Member

    Location:
    Feltham
    correct

    r2 is end to end
    R2 is when joined together
     
  14. haptism
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    haptism Regular EF Member

    Location:
    SW. London
    Thanks all, and thanks for your patience and goodwill,
     
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  15. Risteard
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    Risteard Electrician's Arms

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    Derry, Ireland
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    Because with it all connected in parallel it will be double the cross-sectional area and half of the length.
     
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  16. Pete999
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    Pete999 Trusted Advisor

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    Agree totaly
     
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  17. Hellmooth
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    Hellmooth Electrician's Arms

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    r1 rn and r2 will tell you if your ring is interconnected?
     
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  18. Pete999
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    Pete999 Trusted Advisor

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    Eh?
     
  19. sparksburnout
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    sparksburnout Electrician's Arms

    Location:
    Notts
    Pete demo one of your videos quick.....
    No sod it I am going to revert to lyrics from the great man, all together now:
    Has he lost his mind
    can he see or is he blind?
    Is he alive or dead
    Has he thought within his head?


    Sorry been at the home brew again
    Come on FFS
     
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  20. Pete999
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    Pete999 Trusted Advisor

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    Love it
     
  21. Pete999
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    Pete999 Trusted Advisor

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    Been on the red and she relented and poured me a nice slug of Single Malt could be a bit tender in the morning
     
  22. Pete999
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    Pete999 Trusted Advisor

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    But that doesn't retract from WTF
     
  23. sparksburnout
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    sparksburnout Electrician's Arms

    Location:
    Notts
    What was it?? You tried any of that Welsh stuff yet??
    And how do you get your Mrs to "pour me a slug"?? I just get "I thought you were having a night off it today?"
     
  24. sparksburnout
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    sparksburnout Electrician's Arms

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    Notts
    Or was it supposed to be "A day off it tonight". Oh well....
     
  25. hightower
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    hightower Electrician's Arms

    Location:
    Durham
    I'm with @Hellmooth@Hellmooth and @Pete999@Pete999 on this one - your RFC testing is a 3-stage process. r1, r2, and rn values are pretty meaningless without a valid test in the other two stages.

    @jackhammerJIM@jackhammerJIM R1+R2 doesn't prove polarity on it's own. If you only carry out R1+R2 you would not see a L-E reversed. You need to carry out an R1+RN as part of the process which will then fully prove polarity.
     
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  26. lemonkettaz
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    lemonkettaz EF Member

    Location:
    United Kingdom
    r1 resistance of line, r2 resistance of cpc, rn resistance of N conductors

    R1+R2 resistance of the circuit at furthest point, in a ring though should all be the same (every point)

    Zs = r1 + r2 / 4 is not right

    Zs = Ze + (R1+R2)
     
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    Last edited: Jan 12, 2017
  27. Pete999
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    Pete999 Trusted Advisor

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  28. Pete999
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    Pete999 Trusted Advisor

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    See Mate I relented, couldn't resist, did 2 vids just to be sure hope you like it (for sparksburnout) may try and find some of that Welsh gear you are harping on about, :p:oops::)
     
  29. telectrix
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    telectrix Scouser and Proud of It Trusted Advisor

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    Welsh gear you are harping on about

    thought harp was irish (guinness). :mad:
     
  30. Pete999
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    Pete999 Trusted Advisor

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    No mate sparksburnout was extoling virtues of a Welsh Malt:oops:
     
  31. DPG
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    DPG Electrician's Arms

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    S Yorkshire
    I thought Harp was a lager from the 80s. I remember the adverts - 'Harp - Stay Sharp, to the bottom of the glass'. Christ, why do I remember crap like that! Daz
     
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  32. Pete999
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    Pete999 Trusted Advisor

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    Harping on (you know going on about something) crikey wish I hadn't bothered, but I aint going to harp on about:mad::oops::p:)
     
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  33. westward10
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    westward10 In echoed steps I walk across an empty dream. Electrician's Arms

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    Northamptonshire
    I remember that, tis from Ireland though.
     
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  34. sparksburnout
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    sparksburnout Electrician's Arms

    Location:
    Notts
    Penderyn it is, lovely stuff. Tesco's had it on offer before xmas.
     
  35. sparksburnout
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    sparksburnout Electrician's Arms

    Location:
    Notts
    Must be an age thing, I always seem to recall such rubbish during monotonous periods.The people who come up with these buzz lines obviously know what they are doing if it stays in your memory! Bounty, a taste of paradise.......
     
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  36. Risteard
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    Risteard Electrician's Arms

    Location:
    Derry, Ireland
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    Walsh Electrical Services
    Indeed it is. And full of gas.
     
  37. Risteard
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    Risteard Electrician's Arms

    Location:
    Derry, Ireland
    Business Name:
    Walsh Electrical Services
    Harp still exists. As stated it is owned by Guinness (Diageo). It is (or at least was) brewed in the Great Northern Brewery.
     
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  38. Pete999
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    Pete999 Trusted Advisor

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    While we are off piste so to speak anyone remember Double Diamon, or Red Barrel??;)
     
  39. sparksburnout
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    sparksburnout Electrician's Arms

    Location:
    Notts
    "A pint of the midlands" - oh actually that might have been M&B?
     
  40. westward10
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    westward10 In echoed steps I walk across an empty dream. Electrician's Arms

    Location:
    Northamptonshire
    Wasn't Red Barrel by Watneys, my mum still has a little red barrel keyring.
     
  41. sparksburnout
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    sparksburnout Electrician's Arms

    Location:
    Notts
    Yeah defo
     
  42. Pete999
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    Pete999 Trusted Advisor

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    Yes that's right I'll have a pint of Red Barrel please
     
  43. Pete999
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    Pete999 Trusted Advisor

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    What about a Brown Top (bottle of brown ale and topped up with bitter
     
  44. westward10
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    westward10 In echoed steps I walk across an empty dream. Electrician's Arms

    Location:
    Northamptonshire
    And Double Diamond works wonders.
     
  45. Pete999
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    Pete999 Trusted Advisor

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    All it did for me was to give me the runs
     
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