I've just installed a Reson8 (replacing a v. old bell box).

 

I've used a 4 wire connection (from Optima Compact panel) as that's what was already in place and have not bothered with the strobe (not too sure I see the point in the strobe anyhow).

 

As before, I broke into the last part of the wiring (inside the bell box) that fed the siren unit itself [the red (+ve?) wire] to route via an internal emergency cut-off switch. 

 

With the emergency cut-off switch in the on position all works as one would expect. With the emergency cut-off switch in the off position I would have expected the siren to be silent, But it isn't. A low level siren is omitted (and as as far as I can tell it is coming from the siren unit rather that some small unit secreted in the SAB module).

 

Can anyone explain why (how) this happens?

 

Thanks.

 

 

 

If its an SAB module with battery backup, if you diss the power to the bell via the emergency cutoff it will ring as it thinks someone has cut the wire to the control panel.

To be clear, what I'm saying is that I've broken into one of the two wires (the red wire) that run from the SAB PCB module inside the bell box to the piezo sounder unit. 

To be doubly clear, see diagram - wire broken into is marked with an arrow.

 

http://www.arbat.site88.net/images/TEMP/Reson8.jpg

The sound you're hearing is probably the piezo drive circuit. You do realise that if your sounder is ripped off the wall then your modification will render it useless?

Because of the signal used to drive a piezo, this is bound to happen.

This should NOT be done, for many reasons.

If you wish to have a sounder that you can isolate then you need to buy a better sounder with an engineers hold-off option.

@antinode - yes I'm fully aware (in doing this one weighs up the pros and cons).

 

@sixwheeledbeast - please could I ask you to elucidate on your two points:-

 

   "Because of the signal used to drive a piezo, this is bound to happen."

 

  "This should NOT be done, for many reasons." 

 

Many thanks

I'm out

The piezo drive circuit is very high voltage. Id you need a better switch but i wouldn't do this.

As James, that wire comes from the piezo driver circuit.

This is a horrible noisy AC voltage that will pass through some switches.

This should not be done mainly due to if the switch fails the bellbox will also fail.

I have no idea on the exact voltage contact rating of your switch or one that you "would" require.

Alarm systems should not be designed to have built in override switches it defeats the point.

Also the bell now cannot be returned if any other part fails.

Do you know if the piezo driver circuit will be damaged if there is no load on it?