Blinking red LED; C&K MD's

Dec 04, 2010 8 Replies
C

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?


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J

Ummmm In the DTS 420/435/450 installation instructions, mentioned on pages 2,8 and 10, it says that a flashing Red LED is a micro wave failure indicator. It even mentions that the flashing red LED will override the disabling jumper for the red alarm LED.

The installation instructions are just a small 18 page booklet.

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J

All the C&K dualtec motions work the same. The red flashing LED means microwave failure.

Jim Rojas Technical Manuals Online!

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B

And that is why you got the takeover. They didn't want to pay their old company for new sensors.

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J

Well ...... technically they still have Infra red detectors.

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M

Hey maybe they supplied the internals for the old Detection Systems DS835 :)

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J

Anyone hear a ..... "Thank you"?

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C

Thank you. I 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?

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J

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.

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