2 pir sensors to run a set of four lights

Discussion in 'Electricians' Talk' started by Brian Lightfoot, Jan 3, 2014.

  1. Brian Lightfoot

    Brian Lightfoot New Member

    I am looking to install 4 outside lights and wish to have them activated by a stand alone PIR Sensor. However to cover the range there is the need to install 2 sensors to detect from different areas. Can anyone advise if this is achievable, which is the best PIR's to use and how I would wire them up.

    Any help greatly appreciated
  2. wally

    wally Screwfix Select

    Hi, You can wire 2 PIRs in parallel normally using 3 core & earth cable. The PIRs I always use & have done for the past 10 years ( Timeguard MLB3000) are very good
  3. FatHands

    FatHands Well-Known Member

  4. Brian Lightfoot

    Brian Lightfoot New Member

    Many thanks for your responce

    Can you explain what you mean by in Parallel or do you have a wiring diagram for this
  5. Rulland

    Rulland Well-Known Member

    Basically the 'switched' output on each PIR is joined together and the lights you are controlling are fed from the output on one PIR or the other, either PIR when operated will then switch the connected lights on.
    Obviously both PIR's will require a live and neutral supply as well, this is where the 3 core and earth comes in:

    3-Switched live to lights
    Brian Lightfoot likes this.
  6. Brian Lightfoot

    Brian Lightfoot New Member

    Many thanks for explaining this really appreciated.
  7. Rulland

    Rulland Well-Known Member

    You're welcome.
  8. Brian Lightfoot

    Brian Lightfoot New Member

    I propose to add a switch prior to the first PIR in case I need to switch off the lights for maintenance purposes. I was following this diagram below for wiring, but the wiring from the switch to the PIR is a bit confusing,


    The diagram shows live into switch and then switched live to L1 on PIR. But it also shows the mains live continuing to live on the PIR. How is this achieved? Currently I have 3core from consumer unit to switch and out again, neutrals together, earths together and the two lives into switch. my question is, how is this then wired into the PIR?

    Any advice appreciated
  9. wally

    wally Screwfix Select

    As you say , you need isolation for maintenance, I always fit one but I've come across many where they have not put one in. Your isolating switch can be a single pole light switch which just connects into the main live at the beginning breaking or making the circuit. The additional switch they show bypasses the detector & puts a direct supply on the light fittings. This was quite common years ago so you could keep the lights on without waving your arms about in front of the detector every few minutes to keep the lights on. It can be retained if you wish & is a good method but most detectors nowadays do the overriding electronically by flicking the main on/off switch quickly i.e. on/off/on within 2 seconds to override or switch off for 10 seconds to go back to auto but timing will differ between detectors, the leaflet will explain.
    Brian Lightfoot likes this.
  10. deanalewis

    deanalewis Member

    Hopefully this diagram will help you.


    Attached Files:

    Brian Lightfoot likes this.
  11. Brian Lightfoot

    Brian Lightfoot New Member

    Thank you, I realise what the switch is doing now, but like you say dont need it give the lights direct supply. Have wired up as you say and all is working fine
  12. Brian Lightfoot

    Brian Lightfoot New Member

    Thank you everybody all fixed and working:):)
  13. Rulland

    Rulland Well-Known Member

    That's what we like to hear.

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