Wiring help with older Gira Dual Q Smoke detectors

[DaveG]

I have 4 older installed Gira dual smoke alarms battery only version without the 230v mails base units. I assume I should be able to power these from an external DC source given I can’t source the base units . All searches give ‘no longer available’ The detector has a 3 pin input one marked as common, the second as the signal pin for networking and the 3rd pin has no marking, nor does any of the documentation for either the detector or 230v base unit. I am assuming the 3rd pin and common is for dc input from the base unit but I have been unable to find any documentation either for the detector or the optional 230v base unit. When I installed these I put in a spare 3rd wire so hoping single external supply would do the job if I can validate input required. Thanks for any input.

[jousch]

If your battery powered version has a 9V block battery built-in then I would order 9v block battery connectors and would power all devices via two wires from a central PSU with 9V DC or a case for a 9V block battery ! I assumed you habe the version where no battery change is allowed by the manufacturer.

as the device has a limited life time this would be the cheapest thing.

German but a good video about changing the battery https://youtu.be/CPNLw_RaHYY.

[DaveG]

Thankyou for your comment Grüße. Yes I have the version with the built in block battery that indicates the battery cannot be replaced. I had already opened one of the units and can see you can actually replace the battery but you just have to be careful not to damage the plastic housing when opening.
my preference is to leave the fixed batteries in place and also power the units from a central PSU. Given the units have the option of plugging directly into a 230v base unit with connection only via the 3 pins , I assume the unmarked pin is used for the external supply. If I can just find out what voltage it us expecting on that 3rd pin. I could guess it may be 9 v DC but I really want to confirm what the output voltage is form the separate 230v base units. I have already pre wired my installation link all units via the 3 wires so adding the central single psu will be easy once I can find correct input voltage. Thanks again.

[DaveG]

After much searching I have located a long thread on this topic in German. Thanks to google translator I think I have my answer. Seems the 3rd unlabelled terminal on the detector is a +12v DC input. As I’ve already linked all detectors via the 3 inputs, adding a single suitably rated 12v PSU should do the trick.

[jousch]

nice! you can post your outcome later as a tutorial in german or english tutorial channel. maybe some picture :-)

[jousch]

I would also translate an english version to german. If this is some motivation for you :-D