Zs=Ze+(R1+R2)

Discussion in 'Electricians' Talk' started by kraftwerk, Jun 20, 2005.

  1. kraftwerk

    kraftwerk New Member

    so when you do an electrical test and you have the zs and ze,do you need to physically test for r1+r2 or can you calculate it,say at a lighting point ???
     
  2. ban-all-sheds

    ban-all-sheds New Member

    You could calculate it, and hope that you'd done nothing wrong with the wiring.

    Or you could measure it and be sure.
     
  3. ban-all-sheds

    ban-all-sheds New Member

    I've just realised i didn't read your Q at all well - apologies.

    In your example, how do you "know" Zs and Ze?
     
  4. Rabbit Rabbit

    Rabbit Rabbit New Member

    Not really -

    (a) you NOT then testing the continuity.

    (b) you not testing the polarity (dead).

    (c) as anyone who has done the C&G 23891 will know one of the popular questions is "when can Zs be LESS than Ze given that Zs = Ze + (R1 + R2)"? hint: No not cryogenics.
     
  5. kraftwerk

    kraftwerk New Member

    by testing and measuring it,ze at origin and zs at furthest point.
     
  6. kraftwerk

    kraftwerk New Member

    doesnt the zs test check the continuity of the earth ?
     
  7. pdcelec

    pdcelec New Member

    Not necessarily since the earth path may be the gas pipe!
     
  8. Rabbit Rabbit

    Rabbit Rabbit New Member

    Well Done pdelec YOU pass on that question above.
     
  9. arcticfox1

    arcticfox1 New Member

    IF your an electrician and you have got your 2391 then you should know the answer-your probably a lazy **** who works for a local council
     
  10. Short Fuse

    Short Fuse New Member

    Earth loop impedence test isnt it
     
  11. kraftwerk

    kraftwerk New Member

    another mate who knows it all
     
  12. sparky h s e

    sparky h s e New Member

    not many councils employ their own sparky now ,you must be referring to LONDON ?
     
  13. Short Fuse

    Short Fuse New Member

    if u have "The Electrician's Guide to Inspection and Testing Based on BS7671:2001 Incorporating Amendments 1 & 2, 2004 16ht Edt" read from page 42 - 47.

    Ze is the part of the earth fault loop impedance external to the installation (the impedance of the supply)
    R1 is the resistance of the comsumers phase conductor from the origin of the circuit to the most distant part of the ciruit
    R2 is the resistance of the comsumers protective conductor from the origin of the circuit to the most distant part of the ciruit

    taken from page 39 of "The Electricions Guide to good electrcial practice Based on BS7671:2001 Incorporating Amendments 1 & 2, 2004 16ht Edt"

    so no i dnt know it all
     
  14. kraftwerk

    kraftwerk New Member

    was talking to arctic fox
     
  15. Short Fuse

    Short Fuse New Member

    next time kraftwerk be more specific to who you address your sacry comments to
     
  16. arcticfox1

    arcticfox1 New Member

    Kraftwerk was being sarcastic towards me calm down shortfuse
     
  17. notaknowall

    notaknowall New Member

    i thought you were all competent sparks... not fit to wire a plug me thinks.
     
  18. Rabbit Rabbit

    Rabbit Rabbit New Member

    lol competent! ya joking refer to the thread headed "Idiots" we pro-sparks know who they are.
     
  19. kraftwerk

    kraftwerk New Member

    old not pro
     

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