How to Make a Relay Return to Previous State

There are only two ways to have relays return to previous state after a fire alarm.


Option 1 – Have 2 relays in parallel controlling the lights.

  • First relay is controlled by the fire alarm.
  • Second relay is controlled by a schedule or switch.
    • If the second relay is on when the alarm triggers on, then it will remain on when the alarm resets.
    • If the second relay is off when the alarm triggers on, then it will remain off when the alarm resets.




Option 2 – Implement “phantom relays” (downside to this is that 2 hour override time out will not be possible)

  • Phantom panels are added in “relay properties”
  • Go to the control card in relay properties and add the phantom panels. Leave offset to zero.
    • Note - # of phantom panels should match the size of the control card. (i.e. GR2432 = 4 , GR2448 = 6)
    • The phantom panel will take the address that is right after the control card’s address. Make sure that other devices in that will be moved to a different address. (i.e. if LCP1 is at address 11 – 16, the phantom panel will be at address 17 – 22)
  • Map a new LCP designation to the created phantom panel
  • Add each of the phantom relay to the Schedule/Chelsea switch button that controls the lights.
    • Example; if BTN1 controls LCP1:R1 -> add the corresponding R1 from the phantom panel

      BTN2 controls LCP1:R22 -> add the corresponding R22 from the phantom panel

      BTN3 controls LCP1:R48 -> add the corresponding R48 from the phantom panel

      The same would go for a schedule.

  • Change the all on group controlled by the DigiLink input to a “maintain + blink” group with -> 5sec timer, 1 sec blink



Sequence of how this works;

  • Someone presses BTN1 which turns on LCP1:R1 (the lights), as well as phantom panel R1
    • Phantom panel R1 disables the timer functionality of LCP1:R1
  • An Alarm condition will trigger the maintain + blink group via contact closure which turns ON all relays
  • After the alarm, contact opens which then turns OFF the maintain + blink group
    • All relays will go straight to “blink time out phase” which will time out in 1 seconds and then shut off
    • Since LCP1:R1 and the matching phantom relay were previously on prior to the alarm, this relay’s timer mode is disable and therefore will stay ON
Was this article helpful?
0 out of 0 found this helpful
Have more questions? Submit a request