There have been many questions on relay operation in the past. Hopefully, this little article should provide clarity on their operation.

 

The Ax60 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.  

There are two fail-safe relays, each capable of switching a supply of up to a maximum of 30V DC. 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)

  1. When the Ax60 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
  2. When the Ax60 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
  3. When the Ax60 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 of the device when configured to Fail-Safe


Common questions

If an Ax60 looses power will it be able to activate a solenoid valve?

Fail-Safe: If the solenoid valve power circuit is connected to the COM and NC contacts: When the system is powered down, the solenoid will energise, in normal operation, the solenoid will de-energise, in alarm or fault conditions the solenoid will energise

If the solenoid valve power circuit is connected to the COM and NO contacts: When the system is powered down, the solenoid will de-energise, in normal operation, the solenoid will energise, in alarm or fault conditions the solenoid will de-energise


Fail-Unsafe: If the solenoid valve power circuit is connected to the COM and NC contacts: When the system is powered down, the solenoid will be energised, in normal operation, the solenoid will remain energised, in alarm or fault conditions the solenoid will de-energise. 

If the solenoid valve power circuit is connected to the COM and NO contacts: When the system is powered down, the solenoid will be de-energised, in normal operation, the solenoid will remain de-energised, in alarm of fault conditions the solenoid will energise.