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Conduit requirements and cable type

Former Community Member
Former Community Member

I’m in the process of installing seven hard wired fire alarms into our property all of which have to be interlinked.



I intend to re use a now empty steel conduit that runs from right beside our consumer unit up into the loft space. The steel conduit at its point of entry into the loft terminates there presumably the rest was removed in the past. I want to run a cable from there which will have to do an up and over brickwork in the loft.



My first question, is it acceptable in compliance with electrical regulations to simply clip the cable to the brick at the mortar joints or do I have to or even if strictly not necessary should I, put the cable in PVC conduit? This area is not trafficked.



Once I have crossed the brick work and come down to the first alarm, from there I intend to run a cable down the near center of the loft adjacent to the walkway in pvc conduit parallel to the 2 existing lighting circuit conduits located above the joists. I am not going to drill through the joists. At points along the conduit there will be junctions to allow clipped cable not in conduit to be ran parallel to the joists to the relevant alarm. The conduit is going to be a straight run, so my question is having consulted a few sources that state 1.5mm flexible cable not twin and earth must be used in conduit, does it? I understand the reason for flexible cable in conduit with a lot of turns and junctions but this is a straight run.


Thanks


Parents
  • Former Community Member
    0 Former Community Member
    Hi Legh


    Block of flats circa 1950 build. The plan is to not put the cables tee ing off  the junction boxes to the individual alarms in conduit but clip them to the joists. The conduit is to protect the cable as it runs above the joists right next to the main traffic walkway from gable end to gable end. 


    I can earth bond the steel conduit since the MET is right next to the base of the conduit.


    I think the FP cables are a little overkill we have double layer plasterboard on ceilings that was skimmed, I'd hope the alarms would have long gone off before worrying about ordinary cable failing due to fire.


    Neil
Reply
  • Former Community Member
    0 Former Community Member
    Hi Legh


    Block of flats circa 1950 build. The plan is to not put the cables tee ing off  the junction boxes to the individual alarms in conduit but clip them to the joists. The conduit is to protect the cable as it runs above the joists right next to the main traffic walkway from gable end to gable end. 


    I can earth bond the steel conduit since the MET is right next to the base of the conduit.


    I think the FP cables are a little overkill we have double layer plasterboard on ceilings that was skimmed, I'd hope the alarms would have long gone off before worrying about ordinary cable failing due to fire.


    Neil
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