I am the FoH manager of a 1970’s, 500 capacity hire venue. We have recently (last few months) had a complete new fire alarm system that still appears to have a few teething problems. THE SYSTEM Midnight till 08:00 activation of any point will trigger an immediate full evacuation. 08:01 till 23:59 a delay mode is in operation. In delay mode after any point is triggered, we have 60 seconds to acknowledge the problem on one of the panels, which then gives us further 300 seconds till a full evacuation is triggered if no further action is taken (this all took quite some convincing for the engineers to program and can explain separately if people want to know my reasoning). THE PROBLEM is when multiple points are triggered. My strong impression, is that when any second point is activated, they system would instantly go into a full evacuation mode, last week it did not. I am reasonably confident that on previous tests this has happened, but my memory is being challenged by the engineers (I'm not often in on a Wednesday morning and it has been a month since the last time I tested the alarms). The engineers, since being informed about the “problem”, have said that the alarm (during delay mode) will always wait the 60 seconds. THE QUESTION Can anyone let me know, if a fire alarm has a delay mode and there are multiple points triggered, what is the standard cause and effect sequence. For more insight into what happened, the link is to the You Tube video of the test. (FYI, one point has already been triggered in the lower foyer and the second BG to be activated (the one scene in the video) was done so about 10 seconds before the video started)

I agree - the alarm you describe apprears to work on what is often called a 'double knock' system. I've had a few such systems installed over the last 10 years or so, and in each case, whenever two or more triggers are activated, any built in delay is automatically over-ridden and the system goes into full evacuation mode.