hi all,

i am wanting to connect an additional bell box and sound bomb to my system which is already near full capacity, now i know i will need an additional external 12v psu which i will purchase however i realise for the sound bomb (just neg and pos trigger) i will need some kind of relay to connect on the negative trigger cable and wire to the bell output on the panel, now the question i have is what kind of relay is the correct one to purchase for this task? or is there any alternatives to a relay such as using a different trigger method or wiring off the sab module of the new additional bell box?

any advice is much appreciated

 

thanks in advance

I've never fitted soundbombs, theyre pants.

Trigger may take the load depends on the panel.

Relays should be transistorised.

Maybe using a compatible SCB box would save the hassle with the PSU and commoning neg's.

Have you checked your "capacity", I assume you have standby and alarm current values to calculate your battery standby time?

 

thanks for the reply,

 

yeah i realise sound bombs aren't the best but i just want to use it up so it's just not sitting there, and yes i do have a spare bell box which i could use.

as i have purchased the psu would it be possible to connect the sab module directly to the psu except for the tamper and bell/strobe trigger which obviously need connecting to the panel.

 

and i haven't done proper tests but from working out from the devices it's about 950ma if everything is going off and every detector is triggered and keypads in use and i believe my panel has a 1250ma psu i think not 100% on that it's old and could do with upgrading anyway.

 

thanks again

Standby current is equally important for battery duration this should be calculated from your battery size with tolerance for ageing.

In alarm current I would want to keep a decent margin lower than maximum load as a bit of tolerance.

You also have to consider how much current the panel uses to charge it's own battery after a power outage and power itself.

All PSU's in the system need to be at the same potential so they will need a wire between them as I mentioned above.