Security light and overide

Discussion in 'Electrics UK' started by dingodeano, 18 Mar 2011.

  1. dingodeano

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    Hello all.
    Customer wants a pir controlled light in garden. Havent chosen fitting yet although some timeguard ones you can switch on- off quickly for constant use independent of pir.
    However customer dosent want fused spur on wall by nice french doors. is there a security light on the market than can opperate via a switch wire aswell as the pir?
    Thanks.
     
  2. holmslaw

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  3. bernardgreen

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    They can also switch into constant on mode after power cuts or other disturbances to the mains supply.

    My method is to use a PIR without any such programming features and a pair of switches to provide full manual control. One switch removes all power ( Over ride OFF ) the other switch when on links Live to Switched Live from the PIR to put the light on ( Overrides the PIR ) using 3 core plus earth from switches to the PIR and twin and earth to the light fitting.

    I find separating the PIR and the light fitting makes the coverage easier to set up. My prefered PIR is the Steinel IS 2180-2 as its sensing area can be set up to cover irregular shaped areas.

    EDIT type number changed from IS 2180-5 to IS 2180-2
     
  4. shadysands

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  5. bernardgreen

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  6. shadysands

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    Many thanks for the diagram. A great help.

    Just one thing. Does it not damage the PIR when it gets a live input to the output terminal when it is being overidden.

    Many thanks,

    Brian.
     
  7. bernardgreen

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    It is very unlikely that any damage will be caused to any PIR sensor provided that the live supply is still ON to the PIR's Live when the over ride ON is applied to the Switched Live. Therefore the Live to the ON switch must be taken from after the OFF switch and not direct from Live
     
  8. Taylortwocities

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    If I may, Bernard, I suggest a slightly more elegant version.
    I have found that the two switch solution is confusing for some.

    I usually install the following.

    The switch is an MK Grid switch one of these:
    http://www.tlc-direct.co.uk/Products/MKK4899.html

    It is a changeover switch with a centre off. So
    Up is normal (PIR controlled)
    Centre is off and down is over ride (on).
    The above refers to the way I usually install the switch and does not refer to the diagram as I nicked Bernards original!

    There is no problem with the over ride feeding into the switched output from the PIR provided you use a PIR with a relay output (most have this).
     
  9. bernardgreen

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    Taylortwocities' method is more user friendly.

    I have used a three position rotary switch on a panel but that probably would not conform to BS7671
     

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