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False Alarm From Wired Pir


EdGasket

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Ed,

as you cn see, varying approaches mentioned.

given its age we are going ti say the 'newness' has been all used up and a new system is advisable, simply because if the leaps made in reliability and design features such as voice dial units fobs and wire less detection.

If were stood in front of you, having made my investigations and come up empty, i'd be saying i can't guarantee that detector will be reliable, prudence and as a pro i'd recommend replacement over risking another call charge cost due to it, and then having to have a new detector anyway, but your decision.

just checking battery volts on it's own is not going to show very much, as OXO said, it needs a load test, 1 as many do that with a specialised tester, even then its. guess how long the battery will be service effective. Test today fine, but 3 months later it could fail that same test.

your battery is rated in amps per hour @ 12 volts, You could try either removing the battery, putting a car bulb across it and checking voltage, or removing the mains for 15 mins, run the external sirens several times (to cause more load) then measure the voltage on a DVM, anything below 12 volts in either test, new battery recommended.

You have a particular detector activating around the same time, it would seem to me to point more to mains issue (power station changing grid loads) and a weak battery, but could be a corroded or poor connection affected by temperature as heating go's off, in that zone and what i'd also be looking for.

You could replace this detector and all is fine, or find another then plays up. Devices have a working voltage window, production spread means they will fail at certain slightly varying voltage levels. You replace the 'faulty' most sensitive detector, so the next most sensitive one false alarms on mains fail, all just due to a duff battery or faulty charger circuit.

i din't think your panel has more than a rudimentary memory feature, modern panels can give an experience engineer a wealth of info when investigating faults, recording mains drops, shorts, tampers as causes of false alarms, greatly improving accuracy and speed of fault finding, lowering cost of any calls.

Best option is get some free quotes, se who advises from knowledge as from here we are really only educated guessing.

If you think education is difficult, try being stupid!!!!

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Thanks for the more useful replies. I will check the battery again for DC and any AC on top; measure the wiring etc. maybe replace everything with the suggested Optima unit (very good value if it is good quality?). But I would like to see if there is a simple explanation for the false alarms first.

 

I'm still not 100% sure of the best way to measure the wiring resistance. Do I need to jumper the tamper circuit in the panel, then measure the PIR wiring with the wiring disconnected from the panel but with the PIR still connected? ...or do I remove mains, remove battery at the panel first?

 

(Yes I could get a company in but this is a DIY forum and I like to DIY; I have all the manuals, diagrams, and service procedure for the panel ).

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(Yes I could get a company in but this is a DIY forum and I like to DIY; I have all the manuals, diagrams, and service procedure for the panel ).

 

I'd like to point out that this is the DIY section of a Security Installer forum.

Most if not all of the people that replied are in the trade.

Do not just push away advise from experienced engineers, you came here for help remember.

 

I also agree that the system is old and could do with an upgrade.

The very minimum I would do is replace the detector after testing the cabling and controls correctly.

I guess there are no installed readings to use so it will be harder to prove the device, hence replacement.

Doing nothing will only make the system cry wolf.

 

Remember kit has improved greatly in 23 years.

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Leave the pir connected at the pir and remove one of the wires at the panel one probe on the wire the other on the other wire in the panel meter set to ohms

Thanks; obvious really when you think about it. i was just confused by the tamper circuit but that shouldn't matter unless I need to open up the PIR then I'll have to jumper it. I can compare the reading with another PIR that is functioning correctly. If no obvious problem there or with the panel battery, I will replace the PIR. ( Plus also consider a panel change to keep yo'all happy ;) )

 

Thats all for now. Will report back when i get around to sorting it out (have to go away so no time right now); the suspect PIR is switched out for now. Thanks for help and suggestion of a new system http://www.securitywarehouse.co.uk/catalog/index.php?main_page=product_info&products_id=2186

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Simple voltage test at det head would show this.

 

 

 

What now?

Did I miss something that you have picked up that no one else has noticed?

I thought that too, didnt see anything you did ?

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