We are not experts in this area however we would refer you to BS 5839-6 Clause 16.5. We would also recommend you refer to a trade body NICEIC.
16.5 Recommendations for wiring in Grade D and Grade E systems
The following recommendations are applicable.
a) Cables used for the mains supply to smoke alarms and any heat alarms, and
any interconnecting wiring between all smoke/heat alarms, may comprise
any cable suitable for domestic mains wiring.
b) The cables in Grade D and Grade E systems should be installed in accordance
with the relevant recommendations of BS 7671.
c) Conductors used for interconnection of smoke/heat alarms should be readily
distinguishable from those supplying power (e.g. by colour coding).
d) Cables used for wiring of any unmonitored circuits in Grade D and Grade E
systems should be protected against damage in any areas where it might be
subject to impact, abrasion or rodent attack. Protection against mechanical
damage may be provided by the building construction or by installing the
wiring in conduit, ducting or trunking.
Answered by: Nikki - Prysmian
Date published: 2020-11-09
