Home alarm system - external sounder

[Dippy]

I moved into a house not long ago so I inherited an alarm system with problems. I have managed to get the parts I need including a brand new control system PCB (importantly with the default engineering code!), so I'm ready to put it right.

At my last house I modified my alarm system but I had the engineering code so it was easy. Now I'm a bit concerned about this one because I don't have the engineering code so I'm going to have to start by either isolating the power or by triggering the tamper switch on the control box which will obviously set off the alarm.

The internal alarms are one thing, but I really don't want to **** off my neighbours by having the external sounder going whilst I disconnect the control PCB. You see I'm paranoid that once having done that the sounder will still be going because it gets its power from elsewhere!

I don't really want to isolate the whole house power feed, so I need to know how to disable the external alarm.

Is it typical for external alarms to be mains-powered or are they usually d.c. powered from the control unit such that as long as I disconnect the board power and the back-up battery I'll be OK?

 

[plugwash]

external bellboxes usually have a built in battery backup triggered from some kind of tamper loop, i'm not sure exactly what is needed to make a bellbox shut up though.

 

[Lectrician]

Depends on the make - Some makes have built in trickery. A Texecom bell box has a hold off feature which is activated when you pulse the strobe 3 times in quick succession - You can then remove the cover from the sounder, and disconnect the internal battery. Then remove power from the panel. Texecom panels will pulse the strobe for you when you enter eng mode (newer models).

The sounder is powered from the panel, and takes it power from the panel under normal circumstances. If the panel triggers the sounder, it sounds using the panel power.

If you open the sounder, it tells the panel you have opened it, and the panel sounds the sounder as above.

If you remove the power supply to the sounder, it will self activate using it's internal battery - It will not shut up for 15/20 minutes.

If your has not got a hold off, the only way to proceed is to remove the cover of the sounder, and disconnect the cable from the PCB to the piezeo sounder(s) quickly.

 

[securespark]

If your has not got a hold off, the only way to proceed is to remove the cover of the sounder, and disconnect the cable from the PCB to the piezeo sounder(s) quickly.

Or the BU battery...

 

[Lectrician]

If your has not got a hold off, the only way to proceed is to remove the cover of the sounder, and disconnect the cable from the PCB to the piezeo sounder(s) quickly.

Or the BU battery...

Yup - but if you sort the pieze first, you aint gotta worry about the panel supply AND the battery

 

[Dippy]

Thanks guys. Yes it looks like I'll need to get up the ladder first and just put up with a few seconds (hopefully) of alarm before I can nobble it.