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i have just been speaking to a guy with a b&b who needs to have a fire alarm system installed to meet LD2 regs can anyone offer advice about wireless systems as property is a 400yr old listed building.
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as far as i was aware, they now need to have a dedicated circuit. So i cant see the wireless system helping you a whole lot, for the sake of a core the price would be considerably higher. But im not quoting the regulations on that, so id search for it urself.

There was not another thread in the search, so id like to add another query to anyone on this page... Im not majorly clued up on my panel fire alarms. As i understand it the difference between 2 and 4 wire system is the 2 wire combines the smokes and the sounders. Where as you've seperate sounder circuit on your 4 wire...

But what i was trying to find out is.... the wholesaler was quoting us breakglasses 3 times the price, with the excuse the other ones would not work with a 2 wire system... As i understand a breakglass is not much more complicated than a switch. i do not understand how it makes a difference whether the system is a 2 wire or a 4wire is he just feeding me a load of ****?




A standard 4 wire 24v mcp/call point switches a resistance of either 470 or 630 ohm (depending on make) resitance don't know what the resistance of a 2 wire system is always assumed they'd be the same. Are you sure that you've not been quoted for an addressable mcp as they are more expensive


depends on the protocol as well. some MCP's use different resistances. With regards to using a wireless system it WILL meet standards required and there is some very good kit out there to use. with regards to 2 wire systems. depending on the panel you can intergrate sounders beacons and call points onto the same loop if addressable. These get programmed onto the panel as modules and not input devices. On a conventional they are run from two different circuits.


mains powdered battery back aico radio linked smoke and heat detectors comply to LD2 standards if installed in the correct locations. you still need a mains supply to each detector.

Otherwise a EMS or EDA fire alarm system which complies to L2 standard which is fine because its over specified from LD2.

The devices are fully wireless but massivly expensive.

Hop this helps,

  • Thread Starter Thread Starter
  • #7
would the aico detectors need a dedicated supply or could they be fed off nearby light fitting


They can be powered locally but not from an RCD protected circuit.

Not really for radio linked but reg state..

Cables used for interconnecting smoke and heat alarms
should be readily distinguishable from those supplying
power, (for example by red colour coding). Such cables need
not be fire resistant.

Good installation pratice though even if you use 30cm of cable to power locally its best to use red.

Let me know if you need any more info.

How many storys does the building have ? And how many rooms excluding bathrooms \ toilets?

Forgot to say regs say you can power from either socket circuits or lighting circuits. No RCD circuits though.
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  • Thread Starter Thread Starter
  • #9
thanks mate
problem is its a tt instalation so on an earth stake therefor all circuits are rcd protected

off the top of my head 3 story building with 5 guest beds all en suite
dining rm huge lounge kitchen study owners living area inc 2 beds lounge and meet room also boiler cupd


TT system fun, you now have conflicting regs 17th says one thing BS5839 says another :) On the install cert make sure you not that due to it being a TT supply all detection devices have to be rcd protected then you covered.

Maxium radio linked devices is 30 i think.


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