Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 44 replies
  • Subscribers 32 subscribers
  • Views 3758 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Do you install fire alarm systems?

Chris Pearson
Bit of thread drift going on elsewhere, so I have started a new one.


"Do you install fire alarm systems?" - a question which is asked on insurance renewal, but what does it mean?


IMHO, there is a world of difference between providing a mains supply with third core for linking for a couple of smoke detectors and a heat detector in the kitchen on the one hand (i.e. the minimum grade D2 LD3); and a full on panel with separate detectors and sounder etc. (grade A LD2) in a large house. I consider myself perfectly capable of providing the former, but have never attempted the latter.


So where does the threshold lie? I'd be interested in views on certification too please.
  • 0
    The real problem is exactly where fixed wiring and appliance cross over. I think a normal fire panel system (24V normally) is an appliance. The wiring is part of that appliance and does not come under BS7671. Whether the system works in an event is nothing to do with anyone except the manufacturer unless the installation is faulty due to the installer. We have a problem here in that responsibility is being passed around like pass the parcel. The manufacturer makes most of the money. The installer takes the labour charge to fit and to carry out a functional test. If it functions as designed, the install is good, and it is then the problem of the owner to ensure it continues to work and is maintained. Most of these jobs come with a maintenance contract presumably at the manufacturer's risk of failure. However, there is a tendency to go for the small man if there is a claim, which is totally unfair, but is caused by the feature and scope creep of BS7671. The definition of what is covered should be set in stone and be bulletproof by design. The inclusion of ELV wiring etc is foolish, it needs to go, and an exact definition of the scope needs to be added. OK, smoke alarms may be included, but they are actually in the Building regs, as are CO alarms, the necessity of those being even more lost in the noise. None of these should be in an EICR, the regulations are elsewhere and somewhat unfit for purpose anyway. Remember the problems with Grenfell were NOT electrical, that system worked perfectly, it was everything else that one could imagine that went wrong. That is why they are hurriedly rewriting the building regulations, about 20 years too late!
  • 0
    You posted as I did Andy, which regulations are there specifically for smoke alarms? Is the BS listed in the appendix?
  • 0
    The actual electrics of the modern panel alarm is pretty trivial. Either there are 4 wires to the panel per zone (sounders and detectors 2 wires each) or two wires (sounders reverse polarity on the same pair as the sensors - so red may be negative?). The end may need termination resistor(s).

    More complex ones are still 2 wires to each point, but have a unique address per sensor so the reporting can be selective - fire in flat six kitchen is more help than fire in one of a dozen rooms.


    The earth is so that the panel can flag a wire to earth fault if cabling insulation is mechanically damaged- a  positive to earth fault or a negative to earth fault means the cable has been spiked, but the rest of the self test to see the terminator resistor may still pass.


    For installation, knowing if the sensors are the right type, and properly located is a different matter. When is a rate of rise thermal sensor preferred to an absolute temperature one etc... Do you need one in the cieling cavity etc etc.

    Then there is knowing about the correct sort of joint box, and all the attendant stuff. It is not totally trivial.

    The system in something like a block of flats should be looked at once a year by someone who understands all this, but often that may well not include sensor test in individual flats or operating all call points, it may not be practical to get to those on the wrong side of locked front doors.

    M.
  • Former Community Member
    0 Former Community Member
    We normally bring in an outside company who designs and commissions the systems, but we normally do the install work, you can actually do a course for about a week long to be able to design and commission yourself, then you'll no doubt need a copy of BS5839 which isn’t the cheapest of publications.
  • Former Community Member
    0 Former Community Member
    davezawadi (David Stone):

    The real problem is exactly where fixed wiring and appliance cross over. I think a normal fire panel system (24V normally) is an appliance. The wiring is part of that appliance and does not come under BS7671.


    Make your mind up Dave!

    https://communities.theiet.org/discussions/viewtopic/1037/27608#p155414


     


  • Former Community Member
    0 Former Community Member
    Weirdbeard:
    davezawadi (David Stone):

    The real problem is exactly where fixed wiring and appliance cross over. I think a normal fire panel system (24V normally) is an appliance. The wiring is part of that appliance and does not come under BS7671.


    Make your mind up Dave!

    https://communities.theiet.org/discussions/viewtopic/1037/27608#p155414


     




    The output side of the alarm panel is still classed as fixed wiring and also as a safety circuit, it still needs to be installed as all other lv wiring systems in BS7671, needs to be supported correctly etc throughout it’s entirety. We may only record the 230v side on the EIC, however the system itself has another test certificate to record results such as IR and Impedance etc. 


  • 0
    Sparkingchip:

    Hardwired smoke and heat alarms are a fire alarm system and their installation is within the scope of BS7671, you cannot just ignore them when you are doing an EICR.


    If you are not inspecting and testing the wiring for an alarm system of any type for an EICR you have to specifically state on the EICR that they are excluded from the report and the client needs to get a report from a specialist company.


    How an electrician or inspector could justify not inspecting and testing a mains voltage smoke alarm circuit for an EICR is beyond me, as is how they could inspect and test the smoke alarm circuit but not say that the actual alarms are not fit for purpose, because for example they expired several years ago.


    The heffalump trap here is whether you I&T the alarm system - i.e. does it function as it should? If you are going to do that, you will need appropriate training and PI insurance.


    I suggest that it is sufficient to unclip (a sample of) the smoke/heat alarms and inspect the cable and terminations. Then do IR (if you have not done a whole board check), Zs, and RCD (if fitted and not already tested) on the circuit as with any other circuit.


    As for a panel system, I would stop short at inspecting and testing the supply.


  • 0
    Agree with limiting I&T to the supply only.

    Similarly, fine to test fixed wiring for domestic smokes/heats, even to ensure continuity of interconnect core, but should we be responsible for testing the smoke/heat sensors over and above just pressing the test button and ensuring that all alarms sound when doing so?

    Surely testing the functionality or otherwise of s smoke/heat detector is straying beyond our responsibilities under the wiring regulations? If not, then it should be outside scope in my view.
  • 0
    Domestic smoke and heat alarms have mains voltage throughout their circuit. 


    Testing domestic smoke and heat alarms should be carried out following the manufacturers instructions,   by pressing the test button. 


    The expiry date is on a label.


  • Former Community Member
    0 Former Community Member
    Sparkingchip:

    Domestic smoke and heat alarms have mains voltage throughout their circuit. 


    Testing domestic smoke and heat alarms should be carried out following the manufacturers instructions,   by pressing the test button. 


    The expiry date is on a label.


     


    I don’t really do much on domestic side, but don’t they normally have a shelf life of ten years, and if peeps really wanted to test surely buy a can of smoke. 


Community Rules & Guidelines