Re: Blinking red LED; C&K MD's

[Jim <alarminex@xxxxxxx>]

On Dec 8, 1:38=A0pm, cha...@xxxxxxxxx wrote:
> Thank you. =A0I was really waiting for further responses because I'm
> unable to reconcile the answers to the question with my observations
> and experience with these units.
>
> If the blinking red LED indicates a microwave fault, how is it that
> when walk testing the units, hours after powerup, the microwave and
> the PIR LED's both respond to motion and both extinguish when motion
> stops, and why do two units work normally when bench tested?
>
> What are the faults that occur to the microwave portion that causes
> the blinking red LED?
>
> On Wed, 8 Dec 2010 08:48:06 -0800 (PST), Jim <alarmi...@xxxxxxx>
> wrote:
>
>
>
> >On Dec 4, 4:03 pm, cha...@xxxxxxxxx wrote:
> >> Taking over old system containing C&K DT435 and DT460S motion
> >> detectors. Installed NX8E and connected the MD's.
>
> >> PROBLEM: Red LED's on all of the MD's blink continuously every second
> >> or so. Why? Pulsing continues long after power-up. Have powered
> >> down/up several times.
>
> >> Yellow and green LED's cycle on and off as their respective
> >> technologies are tripped, indicating to me that neither pir nor
> >> microwave have gone to sleep. Red LED's light after yellow and green
> >> LED's light, causing normal relay transfer. All appears to be normal
> >> except that after the MD's reset, the red LED continues to flash every
> >> second or so, and never stop. System keypad green ready light
> >> extinguishes when there is movement, and lights when the MD's reset.
> >> indicating MD relays are functioning properly.
>
> >> I have read the 435 manual (do not have a 460S manual), but I did not
> >> see an explanation for the pulsing red LED. Red LED's continue
> >> pulsing long after power-up.
>
> >> Brought two 640S to shop workbench. Applied 12 volt battery, without
> >> charger. No pulsing red LED, even during power-up. All LED's operate
> >> properly. Units perform perfectly.
>
> >> Anyone have an answer?
>
> >Anyone hear a =A0..... "Thank you"?-

Here are some "Could be's"

 I'm not sure if it was these units or not but I think there were
units available with the microwave set at different freq so you could
use more than one in a job.

Are you using two of the units in close proximity to the other? The
microwaves from one may be setting the other one off and vise versa.

After long periods the micro wave wave guides go out of "tune".

Just because the microwave detector portion isn't working, the unit
will still trip when it sees motion because the passive IR detector is
still working. That is .... The micro wave doesn't necessarily have to
be inoperable in the "open" or "closed" condition.