black wire?

Discussion in 'Electricians' Talk' started by arsenalboy, Jul 14, 2006.

  1. arsenalboy

    arsenalboy Member

    I am replacing my 500 watt external security fitting as had problems with the previous one. My supply cable has 4 wires, the normal 3 plus a black wire. The black wire went into the connector block and matched with a double white wire. The new fitting doesn't have white wires and the instructions only tell you do connect the normal 3 to the unit. What is the black wire for and what should I do with it? Needless to say I didn't put the original unit in otherwise I wouldn't be asking!!
     
  2. Ant1981

    Ant1981 New Member

    External switching?
     
  3. X

    X New Member

    What is the black wire for and what should I do with it?

    Finding the other end of the 'black' wire may be a good idea, before any suggestions as to what to do with it.

    It may be a netural... it may not.
     
  4. Ant1981

    Ant1981 New Member

    Yes, careful there tugging on black lengths.

    Best to find where it leads to, as X suggests.
     
  5. ProDave

    ProDave New Member

    I am replacing my 500 watt external security fitting
    as had problems with the previous one. My supply
    cable has 4 wires, the normal 3 plus a black wire.

    What are the normal three then?
    I assume you have a 3 core plus earth cable.
    I also assume it's a few years old, so would be red yellow and blue.

    Or is a recent cable in which case it will be Brown Black and Grey

    Either way, you need to UNDERSTAND how it's connected before you do ANYTHING.

    It COULD be that whoever wired the old light used an "extra" cable to connect directly to the lamp, bypassing the internal PIR to provide an overide facility.
     

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