PIR Tamper Problem

[kathekas]

I have 4 PIR I want to connect to my Texecom 24W panel.

I test the Tamper Loop on each PIR, and there is continuity.

When I connect 3 in series, there is continuity.

When I connect a 4th one there is no continuity, even though the 4th one when tested individually shows continuity. The cable runs are no more than 10m each.

I and using a multi-meter to test them.

New battery in mult-meter.

Please can someone suggest what the problem is?

 

[sparkymarka]

Short on cable to +
Set meter at dc put one probe on 0v in panel and put the other on the tamper pair , if you get 13.0v it's got a short to +

 

[kathekas]

Thanks sparkymarka

The problem is it doesn't matter which are connected - always electrical continuity.

Connect a 4th one and no longer electrical continuity

 

[sparkymarka]

Ok what readings in ohms are you getting on each pair ? Would expect on a 10m run depending on what cable you have used to be 1.0 ohm to 3.0ohm

 

[kathekas]

Thanks sparkymarka SHOCK RESULT

With the meter set to 200k - 4 zones - each zone is recording between 10 and 12 ohm!!!

I am using existing wiring which consisted of of 4 PIR and one magnetic door sensor. The panel was Accenta G4 and it appeared to work ok.

Please can you assist?

The PIR are ACTIVB PIR P/N3203507 unfortunatly I have no instructions. I think there are probably Honeywell and came with the panel.

 

[sparkymarka]

Ok ...with the 4 devices , series together what reading do you get in ohms ?

 

[Doggit]

As it's a simple tamper loop, with no EOL resistors etc, it has to be a wiring problem. Disconnets the power and alarm cables from the 4th PIR, and then see if the tamper circuits okay, but have you tried it with a new piece of cabling yet. Can you post a picture of the cabling on the 3rd and 4th pir.

 

[kathekas]

Thanks everyone. The pir's were Honeywell 8IR103.

I have now replaced them with Texecom pirs, the resistance on each wiring and pir is now done to 3.2 ohms.

Once again thanks everyone who tried to help me.