Re: pir false alarms

[Frank Olson <Use_the_email_links@xxxxxxxxxxxxxxxxxxxxxx>]

joble_5@xxxxxxxxxxx wrote:
> Hi,
>
> we have an alarm for 2,5 years now. It is a Rokonet system. The PIR
> detector's used are Pyronix Magnum Ultra.
>
> It worked fine for more than 2 years, but last summer we had false
> alarms almost once per week. Always on the same sensor. Sensor was
> replaced by the installer, but next night there was again a false
> alarm.
>
> The Pir is now replaced by a dual detector, and this detector seems to
> work well.
>
> The next week we had false alarms with both the two other PIR's. So
> they are also replaces by dual's.
>
> Now it has worked fine for 3 months. But the installer sends us a bill
> for the replacement of the first detector. And i think another bill for
> the two others will follow. Together this is the 25% of the price of
> the system! I do not think this is normal after 2,5 years. (The
> warranty of the system is 1 year, but on the pyronix site i read the
> pir detectors come with 5 years of warranty)


Some adjustment to the invoice to take the 5 year warranty on the
detectors may be arguable.  The cost for the service visits (labour
portion) is predicated on the company's standard rates and I doubt
you're going to get them to budge.  However, you can point out that when
the one unit started falsing, they should have replaced all of them at
the same time (or at least given you the option during the service visit
in which the first was replaced).  You may be able to negotiate with
them on that point.


>
>
> I want to argue with the installer but first i want to learn more about
> the problem. So i have some questions:
>
> Is it possible that a fly triggers the pir?

Yes.  It is possible for insects to trigger a PIR, particularly if the
units aren't sealed properly and they wind up inside the unit.


> Can this problem be due to bad adjustment of the pir or the use of the
> wrong lenses?

Without actually viewing your installation, I doubt anyone here will be
able to answer that.  There are some considerations required for
detector placement and they're pretty "standard" across the board.  They
include such obvious things as:

Don't have the detector "view" a window (particularly one that the sun
shines in to);
Don't point it at hot air vents or curtains that might be subject to
movement;
Don't point it at a ceiling fan;
Adjust the lens (most often the board) so that it's not viewing "infinity";
Ensure large pets (or even small ones) don't get much closer than 10'
from the sensor (if you have to, block the lower lens elements, or the
detection zones that are viewing couches or other tall objects they
might jump on), even on so called "pet immune" detectors.


> Can the reason be in the rokonet system instead of in the PIR's?
> Any other ideas???

I've had instances where a wire's come loose.  Make sure all the wire
terminations are tight (on both ends).  This is something the tech
should have checked first.