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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Technical Advice => Topic started by: Allen Higginson on July 10, 2008, 03:28:13 PM

Title: Detector Mix in Ext. Systems
Post by: Allen Higginson on July 10, 2008, 03:28:13 PM

It has always been common practice to have a mix of optical & ionisation detectors on an automatic extinguishing system - is this still the case??

Title: Detector Mix in Ext. Systems
Post by: Pottius on July 10, 2008, 09:46:10 PM

it's still common practice to do it that way, so as to detect different types of fires.

Title: Detector Mix in Ext. Systems
Post by: Galeon on July 11, 2008, 01:56:07 PM

Will be the case , until the ion disappears , which is bound to happen shortly

Title: Detector Mix in Ext. Systems
Post by: Allen Higginson on July 11, 2008, 02:03:51 PM

Fair enough.
Cheers

Title: Detector Mix in Ext. Systems
Post by: Galeon on July 12, 2008, 01:25:22 PM

Buzz ,
I have come across an analogue set up with optical only , which was coincidence to a 2 zone gas firing unit , have also seen an increase in the sprinkler side pre action sets covering rooms.

Title: Detector Mix in Ext. Systems
Post by: Allen Higginson on July 12, 2008, 08:41:48 PM

Quote from: Galeon

Buzz ,
I have come across an analogue set up with optical only , which was coincidence to a 2 zone gas firing unit , have also seen an increase in the sprinkler side pre action sets covering rooms.

Yeah,well we have done this firing an old Mather & Platt  4+2 system via zoned I/O's with XP95 Opticals.I think it's down to an assesment of false alarm risk as well as what is the most anticipated type of smoke that you atre trying to detect.I'm still of the belt and braces school of detection in these situations but I suppose we all have our own ideas,eh??

Title: Detector Mix in Ext. Systems
Post by: Galeon on July 13, 2008, 11:07:29 AM

Funny that I think the same way , and I remember Jubblies