On getting the odd false alarm on our BRK 670MBX Mains powered, wired interlinked Ionisation Smoke Alarms, batteries OK, blew out minimal dust but still bleeping, so time to replace.
Found that Ionisation type alarms were now out of favour, looked for suitable replacements. The HiSpec Fast Fix PE?FF10 mains Interlinked Optical Smoke Alarm from our local Screwfix (907RG) looked promising at first, but the wiring diagram https://www.free-instruction-manuals.com/pdf/pa_3632041.pdf is unclear regarding wiring.
Like our existing alarms, there are three terminals, Live, Neutral and Interconnect on a plug in connector, but also an Earth Terminal, which seems strange since these alarms are Class II Apparatus.
In our case there are just three wires visible, possibly the then unused ecc wire was cut short where the 3-core+E was connected to the pre-wired 3-pin connector.
Possibly (likely) that this Earth Terminal is just a terminal to anchor the unused ECC, but is it required for interlinking?
Clive
