Mains Powered Optical Smoke Alarm with Alkaline Back-up Battery - Aico Ei146

We recommend using an optical smoke alarm in hallways, as these are less likely to go off because of cooking fumes from a connected kitchen. Optical smoke alarms are also ideal for living rooms, dining rooms, bedrooms, as they are good at detecting smouldering fires from soft furnishings. For landings we recommend ionisation alarms. Heat alarms are designed for kitchens and garages. No alarms should be installed in bathrooms.

The Ei 140 series with radio-interlink bases would be suitable for this application:
Ei168RC/141 ionisation: best for landings
Ei168RC/146 optical: best for hallway, living rooms etc
Ei168RC/144 heat detector: best for kitchen and garage
Alternatively the Ei160 series (again with radio-interlink bases):
Ei168RC/161RC ionisation: best for landings
Ei168RC/166RC optical: best for hallway, living rooms etc
Ei168RC/164RC heat detector: best for kitchen and garage
There are also battery operated radio-interlinked smoke alarms available (See Ei3100RF and Ei600RF series)

For the mains supply of the first unit a 2-core earth cable would be sufficient. For the connection between the alarms a 3-core earth cable would be required

Yes, we recommend the Ei261EN. You should also install a Ei159 locator to allow you to find out if the alarm was triggered by CO gas or by fire.

To wire the units correctly you would use 2 core and earth cable to the first unit and 3 core and earth to the interconnected units. The alarms do not have to be earthed but a brass screw connector is provided so that the earth can be safety terminated.