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  1. CDB
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    CDB Active EF Member

    Location:
    UK
    Hi,

    I was doing my r1+r2 tests on a lighting circuit yesterday in a 6 bed house over 3 floors. Approximately 20 points not including switches. Mainly pendants but some light bars etc and almost all LED or low energy halogen type bulbs. Closed circuit r1+r2 values range from 0.88 on ground floor to 3.06 on top floor.

    The lights all work ok. I believe I have found one pendant with a discontinuous earth not picked up on a recent EICR done by a 3rd party, which I will return to this week and fix.

    However, a couple of pendants were giving me values of over 130 ohms when the switch was open (light off), which I check as part of the polarity test.

    Can someone help me understand why these high r1+r2 values might be occurring?

    Thanks

    Chris

    IMG_4494.JPG
     
  2. Ian1981
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    Ian1981 Electrician's Arms

    Location:
    North east
    Have you carried out an insulation resistance test on the circuit?
     
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  3. CDB
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    CDB Active EF Member

    Location:
    UK
    Ah yes, good question. I should have said.

    I have performed a R1+Rn - R2 insulation test and got 130Mohm. Not perfect but acceptable. R1 - R2 has not been done as yet because I don't want to have to remove all the bulbs!
     
  4. DPG
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    DPG Electrician's Arms

    Location:
    S Yorkshire
    Are you confusing readings somewhere? You mention a continuity reading of 130R and an IR reading of 130M. Is it just coincidence you have similar results? (I know they're a factor of a thousand different, bu tyou know what I mean).
     
  5. Risteard
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    Risteard Electrician's Arms

    Location:
    Derry, Ireland
    Business Name:
    Walsh Electrical Services
    You're reading through the lamps back to the neutral bar.
     
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  6. CDB
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    CDB Active EF Member

    Location:
    UK
    No its just a coincidence. I've got two pendants its happening on. one is reading around the 130 mark and the other is at 150.
     
  7. CDB
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    CDB Active EF Member

    Location:
    UK
    Can you explain what you mean. Sorry.
     
  8. westward10
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    westward10 Please don't bore me with your life story. Electrician's Arms

    Location:
    Northamptonshire
    Turn the switches on, why have you got them off. You have lost the R1 return at the light with the switch off.
     
  9. CDB
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    CDB Active EF Member

    Location:
    UK
    You misunderstand. This is for just one of the two problem pendants. With the switch closed/on I'm getting 2.89ohm but with the switch open I'm getting 150ohm when I would expect to see >2000ohm (open circuit) as I do for all of the other pendants.
     
  10. westward10
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    westward10 Please don't bore me with your life story. Electrician's Arms

    Location:
    Northamptonshire
    Do you have all the lamps removed.
     
  11. CDB
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    CDB Active EF Member

    Location:
    UK
    Nope but I'm using the same method on another 18 pendants on the same circuit and getting open circuit when The switch is open/off. And many of them have the same model of bulb so why would these two be different?
     
  12. Pete999
    Online

    Pete999 Trusted Advisor

    Location:
    Northampton
    Do you mean R1+R2? r1 r2 and rn are for ring finals only
     
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  13. Des 56
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    Des 56 Trusted Advisor

    Location:
    Gliese 581C
    Its hard to follow your description of what is your situation but here 's a try

    The only thing you are removing when you switch off are the switch live back to the pendant and the switch contacts
    If you are now getting 130 ohms where 1000s were expected,it seems to me it can only be via the open switch
    Have you measured the switch itself as a separate item
     
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  14. static zap
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    static zap Regular EF Member

    Location:
    west midlands
    Comparing cold bulb and 130R ,just leaves heat damage ,
    causing tracking somewhere ,or another cause.
    Are the halogens 230V ,or is some 12V converter envolved .
     
  15. Wilko
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    Wilko Gorillas are Great Electrician's Arms

    Location:
    Berkshire
    Business Name:
    Wilko Electrics
    Any 2 way lights in the mix?
     
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