I am replacing a door contact as part of my Optima XM alarm system since it is very old and a bodge job.
How do I find whether it is nomally closed or normally open?
Un-believable, All door contacts are N/C they go O/C when the door is opened, which causes the alarm to activate.
Regards
Nick
Nick, October 2010
C`mon only open ccts now really are pressure mats and how often do we use them?
Even flood warning devices now are NC.
Alarm, October 2010
to be serious,it can be both,depends on how the alarm is configured,the contacts can be set as open to fire the panel,or closed to fire panel,depends on the system config
gts, October 2010
Try the other way around.
Alarm, September 2010
not this time mate
gts, September 2010
But then on reflection - Normally open when not activated - and closed when activated
Peccavi's friend, September 2010
I know nothing of security systems but...
If the sensing device (switch or whatever) was set to have Normally open contacts when the door or window was closed and secure - then if anybody cut the wires and the door/window subsequently opened - the system would not know about it.
My guess therefore is - Normally Closed - opening the door/window or cutting the wires will have the same effect.
