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  1. C

    Amendment 2 and AFDD's

    Burned up connections are typically not the result of arcing, but rather series resistive heating which happen to be behind 95% of all electrical fires.
  2. C

    Amendment 2 and AFDD's

    Right, which at worse case would translate to 1 1/2 cycles on a 50Hz supply and about 2 cycles on a 60Hz supply if I have my math right. The maximum time which an arc fault can persist is 8 half cycles or 4 cycles on a 60Hz supply according to standard UL1699. Testing done by UL in the United...
  3. C

    Amendment 2 and AFDD's

    From what I understand (and could be wrong) a 32 amp MCB has a max Ze of 1.15 ohms or 200 amps of perspective fault current at the furthest point of the socket. 200/13 would be 15 times the rating. Thus 200 amps trips a TDC180 British plug to fuse in under 0.01 seconds...
  4. C

    Amendment 2 and AFDD's

    A parallel L-N or L-E event will blow the fuse. A series event without an outer screen to earth itself out to would technically require an AFDD, however, I do not believe partially severed cords are behind any number of fires. I aslo do not believe that AFDDs accurately detect dangerous arcing...
  5. C

    Amendment 2 and AFDD's

    Do have a time current curve to common BS1363 fuses? The flex itself typically adds only a small amount if impedance to the fault loop.
  6. C

    Amendment 2 and AFDD's

    Thats what the plug top fuse is for, literally. A short in the flex will open the fuse within 3 cycles. Though anyone here can correct me on that if not so in practice.
  7. C

    Amendment 2 and AFDD's

    Funny you mention evidence. In the US, other than cut wire wrapped in glass tape and hooked up to a neon gas transformer in a laboratory there is zero evidence that arcing is behind any residential fires to begin with. There is the case of firefighters opening walls to find smoldering studs...
  8. C

    Amendment 2 and AFDD's

    AFCIs used to have 30/50ma ground fault protection in them, but some of the US manufacturers took it out in favor of looking at the current signature alone.
  9. C

    Amendment 2 and AFDD's

    Any arcing to earth produces a current imbalance which trips the RCD. You don't need to look at the current signature on the active to do that, nor does said current signature analysis need to discriminate between a vacuum cleaner motor vs an actual fault.
  10. C

    Amendment 2 and AFDD's

    You would be correct, AFCI in the US are a constant never ending battle of nuisance tripping. To make matter worse we find burned up splices, screws, terminals and sockets where the combination AFCI breaker (serial+parallel arcing protection) never tripped. With that said I want to simply...
  11. C

    Time Current Curves of Various MCBs and MCCBs

    Nice, thank you for this! :) Do larger MCBs and MCCBs have similar curves? 4.5 times for 10 seconds, 6 times for 5 seconds and 10-20x for 1 second.
  12. C

    Time Current Curves of Various MCBs and MCCBs

    Any links or PDFs? I can get US trip curves online, EU not so much since I don't know where to look.
  13. C

    Time Current Curves of Various MCBs and MCCBs

    Does anyone have a link to various time current curves relevant to UK MCBs and MCCBs in the 16-1,200 amp range? Specifically, how many times the handle rating does it take for each to trip at 10, 5 and 1 second.
  14. C

    IEC 60364 Table 48A

    Does anyone know in what IEC standard I can find table 48A? I'm reading of its existence, but can't actually find it.
  15. C

    AFDDs are a massive fraud

    If this can be merged with the above post:
  16. C

    AFDDs are a massive fraud

    What started AFCIs in the United States:
  17. C

    Steel Awning frame outside EP zone, bondit?

    I can't picture shoes in all cases.
  18. C

    Ze of Generator

    Anyone know? R goes up as shirt circuits move away from the generator.
  19. C

    Ze of Generator

    As I am reading up on it, and I could be wrong, the kw on the prime mover actually drops due to the R going down and the X going up. The current is reactive, and as the voltage goes down the field is "forced" to its max excitation to keep voltage up.
  20. C

    Ze of Generator

    Alright and agree. However, what R & X to I assume for the generator windings when doing the equation to get the total Zs? And what voltage? I know this is a dynamic 4-D scenario, but I want to keep it simple (if practicable) to a 2-D set of equations.

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