Building regs re smoke alarm - isolation

Oct 27, 2007 3 Replies

In replacing a cable nicked by a plasterers float thro PVC capping I wanted to check current regs re smoke alarms.



AICO & BR docs re smoke alarms levels E & D (mains with battery backup) do not require a local FCU/SFCU for smoke alarms run off a dedicated (3A MCB) final circuit.



Q: Is my reading correct - main switch is acceptable?



The smoke-alarm circuit also supplies a burglar alarm & dialler so they are not on RCD/freezer/ext-lighting circuit.


I am surprised that a plasterers float could cut anything as the nails in these usually only protrude 1 -2 mm. The capping and the cable must have been above the surface of the render.

By "nails" I presume you refer to those in a devil float? Is so, you are right that these are unlikely to damage a cable. Damaged caused by an ordinary metal plasterers trowel on the other hand is not uncommon (although less so if there is capping there).

Too many assumptions. o Wall unplastered as far as the corner 150mm cable zone o Corner 150mm zone plastered, smoke cable at edge, no cap o Corner stepped by a mix of wood, coke-breeze & brick

Stainless steel float - corner point will penetrate anything.

As for FCU/SFCU, can not find anything, now plastered. If ever needed it can be MK Edge/Grid on the ceiling.

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