Comelit Addressable Relay Module, 1 Relay Output 240VAC, Isolator 41IOM000/240

Overview

When a fire is detected, other building systems often have to react. Fans stop, doors release, lifts are recalled or a signal goes to another system, and each of those needs a contact the fire panel can switch.

This module gives the panel one such contact on its addressable loop. The commercial fire alarm guide explains how an addressable fire alarm system works with its loop devices.

How it works

• Loop powered: the module draws its own power from the loop and acts on commands from the control panel.
• Volt-free contacts: the relay is a plain switch, so the equipment being controlled keeps its own supply and the fire system stays separate from it.
• On-board isolator: an isolator cuts off a short-circuited section of loop so the rest of the loop keeps working.

Where to use it

With an IP21 rating and a working range of -10 to 60 °C, the module belongs in a dry indoor position, usually beside the equipment it controls.

Common jobs include releasing fire door holders, shutting down air handling, and passing a fire signal to access control or another system.

What the figures mean in practice

• 4A@250VAC: the most the contacts should carry on a mains circuit. Larger or inductive loads, such as motors, are usually switched through a contactor rather than directly.
• 3A@30VDC: the limit on a low-voltage DC circuit, such as a door holder supply.
• 0.18 mA in stand-by: the module's own draw from the loop at rest, which the loop calculation adds to every other device.
• 15÷32VDC: the loop voltage range it works across. Long loops lose voltage, so check the far end stays inside it.

Installing it

• Before you start: as a rule, take the loop out of service at the panel and isolate any mains circuit you will connect to the relay.
• Fixing: fix the enclosure to a flat wall where the clear cover can be seen for inspection.
• Cabling: size conductors to the 0.4 ÷ 2.5 mm terminal range. Fire-resistant cable is the usual choice for the loop, and mains wiring needs a competent electrician.
• Commissioning: set the relay's cause and effect at the panel, then test that the controlled equipment responds.

Planning your system

Where a load such as a sounder needs a monitored circuit rather than a plain contact, a Comelit monitored output module may suit the job better. Other loop devices sit among the fire panel modules and interfaces.

Fire door holders usually need their own low-voltage supply, and a fire alarm power supply with battery standby is the usual way to provide it.

Check the panel's documentation that it supports this module before ordering, and have changes to a fire alarm system designed and commissioned by a competent person.