How do I interface an old alarm system with no voltage contacts (no or nc) to a siren that needs 12

Thread Starter

David Weaver 1

Joined Sep 1, 2019
14
The siren has 12 volt supply to the box. The alarm controller states that the contacts have to have zero voltage.
 

crutschow

Joined Mar 14, 2008
23,335
If the "contacts have to have zero voltage" then I don't see why you would connect 12V to them? :confused:
 

Thread Starter

David Weaver 1

Joined Sep 1, 2019
14
If the "contacts have to have zero voltage" then I don't see why you would connect 12V to them? :confused:
The alarm control unit instructions state that it's Relay contacts, to trigger external siren must have no voltage across them. The external siren needs 12 volts from the control panel to trigger the siren.
 

Thread Starter

David Weaver 1

Joined Sep 1, 2019
14
Where does it state this? On the unit?
Or do you have hook up instructions, or any other details?.
Max.
The alarm control unit states that the built-in external alarm Relay contacts either no or no must have no voltage across them.
The external siren wire diagram shows that it requires a 12 volt signal to activate the diren/ strobe.
 

Thread Starter

David Weaver 1

Joined Sep 1, 2019
14
Where does it state this? On the unit?
Or do you have hook up instructions, or any other details?.
Max.
The alarm control unit instructions state that it's Relay contacts, to trigger external siren must have no voltage across them. The external siren needs 12 volts from the control panel to trigger the siren.
 

Alec_t

Joined Sep 17, 2013
10,362
The alarm control unit instructions state that it's Relay contacts, to trigger external siren must have no voltage across them.
The specification "Latching relay contacts (volt-free)" doesn't mean that the contacts must have no voltage applied: it means that the control unit itself doesn't supply any voltage to the contacts. It's your decision what use you make of the contacts.
 

Thread Starter

David Weaver 1

Joined Sep 1, 2019
14
The specification "Latching relay contacts (volt-free)" doesn't mean that the contacts must have no voltage applied: it means that the control unit itself doesn't supply any voltage to the contacts. It's your decision what use you make of the contacts.
Sorry I never sent the text that was with the the Alarm panel connection block...

IMAG1225~2.jpg

This is were I got the idea that I could not apply a voltage across the contacts.
 

MaxHeadRoom

Joined Jul 18, 2013
19,029
I assume that infers that no external voltage is required and contact closure only is required between input points.
They appear a little vague and certainly could be clearer.
Max.
 

Thread Starter

David Weaver 1

Joined Sep 1, 2019
14
I assume that infers that no external voltage is required and contact closure only is required between input points.
They appear a little vague and certainly could be clearer.
Max.

I agree that it could be better and maybe I need to talk to Honeywell.
I have 12 volts at the siren box and I did not think I could run it through the control box NO snd the when the alarm is triggered the co tacos would close sending the 12 cold to the siren. On cancelling the alarm the siren would cancel!
But the wording made me think that I needed an interface that would supply the 12 volts to the siren from either an open or closed contact from the panel.
But I have no idea what circuit/inyerface I should look for that would not put voltage across the contacts.
 

Thread Starter

David Weaver 1

Joined Sep 1, 2019
14
I agree that it could be better and maybe I need to talk to Honeywell.
I have 12 volts at the siren box and I did not think I could run it through the control box NO snd the when the alarm is triggered the co tacos would close sending the 12 cold to the siren. On cancelling the alarm the siren would cancel!
But the wording made me think that I needed an interface that would supply the 12 volts to the siren from either an open or closed contact from the panel.
But I have no idea what circuit/inyerface I should look for that would not put voltage across the contacts.
Sorry Section should read
NO or NC when the alarm is triggered the NO or NC would operate sending the 12 volt to the siren. On cancelling the alarm the siren would cancel!
 

MaxHeadRoom

Joined Jul 18, 2013
19,029
To me it would seem that especially a Co. such as Honeywell would show a much clearer and detailed typical hook-up.
The instructions are far from clear and certainly not typical, IMO.
Max.
 

Thread Starter

David Weaver 1

Joined Sep 1, 2019
14
To me it would seem that especially a Co. such as Honeywell would show a much clearer and detailed typical hook-up.
The instructions are far from clear and certainly not typical, IMO.
Max.
Thanks again for the help. What I maybe should have said was the the alarm system has its own solar powered wireless siren and over the last few years I have noticed
that in winter it can lose all its power and I am trying to install an additional powered siren. Both the alarm and the new siren are honeywell.
 

be80be

Joined Jul 5, 2008
1,930
I wasted my time The horn hooks up as I posted
In post #2
And that's because the horn on most alarms is based on what you need
And the alarm supply most times can't handle the load of a horn.

You have lot's of horn options anywhere from 6 volt to 24 dc or 12 volt to 120 volt ac just to name some.
 
Top