DSC motion detector --> serial connection --> 4 sensors

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  #1  
Old 09-25-17, 10:06 AM
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DSC motion detector --> serial connection --> 4 sensors

Hi to all !
I have some existing installation where i have 4 sensors connected in serial ( green / white green wires on zones ). The problem is that i can not find those green wires on the panel side.
Or to be more exact, cable is there but if i connect them to panel, i get open zone all the time. I could test wire shortcut but i can not activate all the sensors at one time....

So, i can install new cable to this first floor but i still want to use this serial connection because i dont have any more free zones on the expansion board.

Conclusion:
- how can i test if the serial connection of those 4 sensors is OK ( each sensor is cca 10 meters apart ) and how should i connect them correctly ?
- btw. full green on the first sensor is located on COM.

I saw this thread but here i have 4 sensors:
http://www.doityourself.com/forum/el...-together.html

Best regards and thnx in advance !
 
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Old 09-25-17, 10:15 AM
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Welcome to the forums.

You have four motion sensors that you want to connect to one panel zone. That is possible but is not a good choice. As you've found out.... when one motion isn't working.... none of them do. If you have a zone trip you have no idea which actual detector is the fault.

Each detector needs a 4 wire connection. Two wires for power and two for the trigger.
Do you have all four cables coming back to the panel or is there one four wire cable that leaves the panel and goes from unit to unit ?
 
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Old 09-25-17, 01:55 PM
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Thank you for fast reply ! I really appreciate this because tomorrow i have to test all system.

Picture:
- the picture is on ******* / ihhKik

Answer to your questions:

1.) distance between sensors on the first floor and panel is around 100 meters and i can not drag new cable all the way because there is no option for this, so i have to reuse old wires.

Last installer has used UTP cable and (am not 100% sure), it looks like he has connected one sensor from the lower floor with the sensors on the first floor. The interesting part is that we have pulled new cable on the main floor so there is no way i can use this wires if he has done such setup.

2.) he has used orange / white orange wires for power and all 4 sensors are working. I mean, they have power supply. He didnt use tamper

3.)Do you have all four cables coming back to the panel or is there one four wire cable that leaves the panel and goes from unit to unit ?**** One UTP cable is comming down to the panel. When i connect orange wires to power, all 4 sensors are powered up but when i connect green/white green then i get open zone, all the time.

4.) I can pull new cable some 30 meters and connect this new cable to green/white green but real problem is that i dont know how to check if all 4 sensors are hooked up together. Should i connect NC / C terminals together ( without power ) and test the end on the wires ?. But then again, there is no way that it could show open zone because there was one on the floor at the test time and the zone was constantly open...

5.) i draw some picture that should explain how he hooked up those sensors. Green wires are just for explanation, just my guess how he done it. Btw. can you draw correct serial wiring for this 4 sensors ?. I know am asking much but i guess that this could help a lot of people , and not just me...

Regards !
 
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Old 09-25-17, 02:03 PM
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I can not upload image on the forum. The picture in on ibb dot com / ihhKik
 
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Old 09-25-17, 05:20 PM
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If they used a single multi-conductor to leap frog from one motion to another, then they used a pair to supply power from one detector to the other (in parallel); and ran one of the other pair in and out of the NC/C terminals. The 4th wire is just a pass through until it's connected at the last detector.

Again, this is not an ideal way to do this, because it makes tracking down the inevitable false trips near impossible.

That said, since you (correctly) ran a new 4 conductor to the new motion; connect the first pair to the power terminals on the motion; and the other pair to NC/C.

At the panel end, take _one_ of the zone wires for the zone your are tying to off of it's terminal. Connect that wire to one of the two zone wires coming from your new motion. Take the remaining wire from the new motion and land it on the (now empty) zone terminal. Connect the power wires, and you will have added a 5th motion to the loop (not a great idea, but it will work).

If you want to verify the integrity of the existing circuit, then yes, the easy way is to jumper all of the NC/C connections at the devices, and check the overall continuity of the pair from the head end.
 
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Old 09-25-17, 05:34 PM
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Could not get your link to work. Post your picture directly to the board.
http://www.doityourself.com/forum/el...-pictures.html
 
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Old 09-26-17, 12:43 AM
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Maybe this will work:
Name:  schematicsDSC.jpg
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Old 09-26-17, 02:13 AM
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You have to create a closed series loop. The white just gets carried thru to the last device and is the loop return wire.

I just re-read your first post.... I used yellow.... just picture it as white.
I just re-read the entire thread and see you have cat/8 conductor cable. That wire is really too small but you can double it up.

Use the orange pair for red.
Use the blue pair for black
Use the green pair for green
Use the brown pair for white
 
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Last edited by PJmax; 09-26-17 at 02:38 AM.
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Old 09-26-17, 05:59 AM
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Thanks all for reply !. I will test it today and let you know...

Regards !
 
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Old 09-28-17, 02:23 AM
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I can not make any tests before Saturday.
Before i forget, i have noticed that the sensors are powered from different cables.
Shortly, if i cut down power supply for two sensors, other two will work...

I dont think that this should be any problem, but just for check...
Any input is welcome :-)
TT
 
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Old 09-28-17, 03:06 AM
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The 12v power coming on different cables should make no practical difference.
 
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Old 10-07-17, 02:34 PM
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It's working without problem.
Thnx!
 
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Old 10-07-17, 02:58 PM
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Thanks for letting us know how you made out.
 
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