How to Connect 120-Volt Interconnected Smoke Alarms to a Security System (Kidde SM120X) - Avenger Security

Connect Household Smoke Alarms to Monitoring: Kidde SM120X Considerations

Some compatible household 120-volt interconnected smoke alarms can provide an auxiliary signal through a Kidde SM120X relay module. The relay responds to a smoke signal on a supported interconnect and provides isolated contacts. That contact may be evaluated as an input to a monitored alarm system, but the complete arrangement must be compatible, properly supervised where required and approved for the application.

What the SM120X does

Kidde describes the SM120X as a smoke-alarm relay for specified interconnected models. It is not a smoke detector and does not replace the household alarms. It responds to a compatible smoke interconnect signal, not necessarily to every CO or other event on a mixed network. Confirm the exact alarm models, module instructions and maximum allowed number of interconnected devices before specifying it.

Separate the 120-volt and low-voltage work

The relay module's line-voltage wiring must follow the manufacturer's diagram and applicable electrical rules. The isolated contacts can then be evaluated for connection to an appropriate panel input by a qualified alarm installer. Do not connect a household alarm interconnect conductor directly to a low-voltage panel zone.

Check the whole monitoring path

  • Confirm the installed smoke alarms are compatible and in serviceable condition.
  • Confirm how the panel zone is classified and supervised under the approved design.
  • Identify what happens on AC failure, relay failure and loss of panel communication.
  • Test activation of a supported smoke alarm and the interconnect response.
  • Place the central-station account on test before testing and verify the intended signal with the operator.

Professional monitoring follows account instructions and local response procedures. A relay output alone does not guarantee dispatch or make a household alarm network a code-compliant commercial fire alarm system. For a larger or mixed-use property, a separately designed fire-alarm system may be required.

Review the Kidde SM120X product information and the exact installation manual for the alarms on site. Avenger Security can coordinate the alarm interface and monitoring review for an Austin-area home. Request a system assessment.

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