There have been many questions on relay operation in the past. Hopefully, this little article will provide clarity on their operation.
The CO Clear relays are volt-free and should be seen as automated switches. These can be used to switch power to devices such as beacons, fans etc.
When ordering your CO Clear you will have been given the option of adding one or two relays. There are fail-safe relays, capable of switching a supply of up to a maximum of 240VAC/28VDC, 2 Amps. They are configured by default to trigger on the high alarm, but can be configured to actuate in any alarm or fault condition
Each relay has 3 contacts: A Common contact (COM), Normally Closed contact (NC), and a Normally Open Contact (NO)
- When the CO Clear is powered down, the relay will be de-energised. A connection will exist between the Common Contact and Normally Closed Contact. No connection will exist between the Common Contact and Normally Open Contact
- When the CO Clear is powered on, and in normal operation mode, the relay will be energised. A connection will exist between the Common Contact and Normally Open Contact. No connection will exist between the Common Contact and Normally Closed Contact
- When the CO Clear is powered on, and the preconfigured alarm/fault conditions are met, the relay will be de-energised. A connection will exist between the Common Contact and Normally Closed Contact. No connection will exist between the Common Contact and Normally Open Contact
The animation below should better explain the operation
