Wired Alarm System-problems getting it to work

Discussion in 'Electricians' Talk' started by unphased, May 8, 2018.

  1. peter palmer

    peter palmer Screwfix Select

    To me red and black are the obvious choice for the 12V and blue/yellow for the alarm contact, this is the 4 colours you would have in a 4 core cable so it makes sense to use them. If you wire a tamper with 6 core then use the green and white pair for that.
     
  2. Lectrician

    Lectrician Screwfix Select

    Tampers should not be optional.
     
  3. Rulland

    Rulland Screwfix Select

    Did any of the pirs have more than one cable in them?, was it all 8 core or a mixture?.
    There is the possibility that whoever installed it took a cable to each of two pirs back to a common point or junction box, then used a single 8 core to bring those two zones back to the panel, ie utilising the orange and brown, hence the colour change.
    I would normally run 8 core to the first pir, use blue/yellow as alarm for that device, common up power, joint brown/orange at that pir, then on the second pir brown/orange are alarm. Green/white would be seriesed up for the tamper.
    So at panel, red/black=power
    Blue/yellow=zone 1 eg
    Brown/orange=zone 2 e.g.
    Green/white= tamper=in series with other zone tampers.

    Unfortunately the only real way to confirm is by some intense belling out and trial and error.
     
    Last edited: May 8, 2018
    unphased likes this.
  4. unphased

    unphased Screwfix Select

    Thank you all for your help. Much appreciated. As things turned out, I had wired three of the four detectors reversed polarity. I corrected that and the alarm is now working 100%. Thank you, Lec, for pointing me to that it saved a lot of time on site. The first thing I looked at. :rolleyes:
     
  5. Hollie

    Hollie Member

    Glad you managed to muddle your way through :oops:
     
  6. Pollowick

    Pollowick Screwfix Select

    You have hit one area where there is no standard or consistency ... It has good and bad points though and try to use 6 core or 8 core cable.

    I tend to use:

    0v - Bk with Bn if I need to double up for a long run or high current
    12v - R with Or to double up
    Alarm - Bl
    Alarm - W
    Tamper - Gn
    Tamper - Y
    Bell & Strobe Triggers - Bn & Or

    If reworking or upgrading a system - it is always worth disconnecting everything and then starting from scratch using a specific wiring scheme which could be my own or another defined one.
     
  7. Vin

    Vin Screwfix Select

    Colour codes are a matter of preference but back in the early 80s when I started fitting alarms, PIRs were expensive and rarely fitted in domestic situations, most detection was door contacts and pressure mats which used 4 core cable.

    We used red/yellow as the alarm loop and black/blue as the tamper loop.
    When we did use a PIR or any other type of electronic detector that needed a 12v supply we used green and white as the supply so we could keep the same colour codes for the alarm and tamper circuits.
    I still use this colour system now as it's easy for me to remember.
     

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