Voltage across alarm pair

[saxondale]

Why not check the voltage with it connected and disconnected? About 0v with it connected and open circuit voltage with it disconnected or operated? This would have pointed towards the wiring as opposed to the panel.

just that - experiance again says its the cable (especially as the op said about reflooring - its a standard question to ask about works been done recently) so you check that before the panel

but in this case (though I would have to mock one up first ) I think you`ll either get 13v either way or no change from the expected figures even with the fault

if the cct cable meters out correctly then I would be thinking the reason its not triggering the panel could be because theres a short between 13v or 0v and the alarm cores so even though the relay opens the panel still see`s 13v (or 0v if its on the negative legs) at the return terminal

 

[Spark123]

In your experience, do the panels ever go wrong? Theres only a few resistors which I'd imagine are pretty bomb proof, however I'd imagine the IC could be a bit susceptable to going wrong.
If they managed to spike through 12v or 0v AUX supplies to the alarm cores there would be some odd readings tho there is a nice big resistor to limit current flowing through to the IC.

 

[saxondale]

In your experience, do the panels ever go wrong? Theres only a few resistors which I'd imagine are pretty bomb proof, however I'd imagine the IC could be a bit susceptable to going wrong.
If they managed to spike through 12v or 0v AUX supplies to the alarm cores there would be some odd readings tho there is a nice big resistor to limit current flowing through to the IC.

a good make of panel? very very rarely

the cheaper end of the market ? they go more often but it usually takes an external influence - restoring power cuts when the battery is dead is a classic or lightning to name a couple

shorts between poles are one of those things few engineers look for - its easier when the carpet fitters have been, they usually manage to blow the fuse first LOL