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.
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.