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  1. haptism
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    haptism Regular EF Member

    Location:
    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

    Location:
    Livingston
    Business Name:
    CM Electrical
    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

    Location:
    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 Gorillas are Great Electrician's Arms

    Location:
    Berkshire
    Business Name:
    Wilko Electrics
    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

    Location:
    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

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

    Location:
    cheshire/staffordshire
    Business Name:
    Telectrix
    R2 reading wound not be same as r2.
     
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  8. Wilko
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    Wilko Gorillas are Great Electrician's Arms

    Location:
    Berkshire
    Business Name:
    Wilko Electrics
    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

    Location:
    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

    Location:
    Derry, Ireland
    Business Name:
    Walsh Electrical Services
    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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    Location:
    Northampton
    Agree totaly
     
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  17. Hellmooth
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    Hellmooth Electrician's Arms

    Location:
    Livingston
    Business Name:
    CM Electrical
    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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    Location:
    Northampton
    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

    Top Poster Of Month

    Location:
    Northampton
    Love it
     
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