Aico Switched Input Module, Mains with Lithium Back-up, Hard Wire Interconnect Ei129

What this module does

Smoke and heat alarms in a home normally react to what they sense themselves. This Aico module adds a way in from outside the alarm system.

When the outside device operates, the interconnected smoke alarms sound. It does not detect anything itself.

How it works

• Volt free contacts: these are switch contacts that carry no voltage of their own. They simply open or close, so the outside device only has to provide a switch.
• Normally open and common: the two contacts stay apart until the device operates. When they close, the module passes the alarm signal on.
• Hard wire interconnect: the signal reaches the alarms along a cable, not by radio.

Where to use it

A sprinkler system is one example, which suits homes where a sprinkler flow switch should also set off the alarms. Check the temperature and humidity of the position against the unit's documentation.

A sprinkler or alarm designer should confirm how the two systems are meant to work together.

What the figures mean in practice

• 0.2 W: this is a small continuous load, so it is unlikely to matter on a domestic circuit.

Installing it

• Isolate first: this is mains work, so isolate the circuit and use a competent electrician.
• Siting: fit it on its own with the cover, or underneath an alarm. Allow for the unit's size when sharing a position.
• Testing: operate the outside device, then walk the building and confirm every alarm sounds.

Planning your system

It needs alarms from these ranges on the same hard wire interconnect. If your alarms use radio links instead, this is not the right module.

The instructions for your alarms set how many devices can share one interconnect. Check that limit before adding this module.