Re: Testing Duct Smoke

["FIRETEK" <firetech(change-the-ch-to-k)@telus.net>]

Remove the cover.  Remove the detector.  Pull the sample tubes and ensure
none of the orifices are plugged with debris.  Make sure they're oriented
correctly as you pull them (the inlet tube should have the holes in the tube
facing the towards the high pressure side, the outlet tube should be facing
the "lower pressure" side.  Ensure there's flow through the sensing chamber.
Pull the cover off the smoke.  Ensure the chamber isn't clogged with dust or
debris.  If it is, clean it with isopropryl alchohol (99% pure) and a soft
bristle brush (I like the camel hair shaving brushes).  Use high quality
"Dust Buster" canned air to dry it.  We always use canned smoke to test the
detector.  If it's an ionization type, I'd recommend replacing it after ten
years.  Whether the customer goes for that is up to them.  On the older
Edwards duct detectors, they're no longer manufacturing the actual unit, and
you'll have to replace the entire assembly (which can be a real pain).
There are usually relays which the detector trips (that shut down the fans).
Make sure the voltages on the relays are within the manufacturer's specs.
I've seen a number of installations where they aren't and an additional
relay (or contactor) is required.  Re-assemble everything and place your
inspection sticker with the service date on the cover so it's visible to the
AHJ.

Good luck!!

Regards,
Frank (no, not *that* Frank, the "other one")


<super2324us@xxxxxxxxx> wrote in message
news:1168740207.445753.97070@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Can somebody please tell me how to test a Duct Smoke Detector? I know
> how to test the rest of the system but not the Duct Smoke. Thanks
>