Bell box tamper for two bell boxes

[tim_s_uk]

I have a eurosec CP8L system and two vortex bell boxes which I'd like to fit to the front and back of my house. I have configured the bell boxes so they are only triggered externally (the bell box tamper switch won't trigger the bell box directly). This should allow me to silence the alarm if there is a fault with the bell box tamper switch.
So far I can see the control panel and bell box wire together as follows:

SAB TMP TO Return
Bell Hold- TO Hold-
Bell- TO TG-
Bell+ TO Hold+
Strobe- TO STB-
Strobe+ (Unused)

I am planning to connect the two bell boxes in parallel, which I think should work except for the "SAB TMP to Return" connection. Is there a way of wiring the return from each bell box to the control panel such that tampering with either of the bell boxes will cause a tamper alert at the control panel (without directly triggering either bell box)? The control panel can then trigger both bell boxes if the system is armed.

If I connect the bell box return signals in parallel then both bell boxes would have to be tampered with before the the control panel was signalled. I could rewire the tamper switches in series, but I wondered if there was a standard solution. Thanks in advance.[/code]

 

[Europlex]

Have not got the time now I'm afraid, but, they SHOULD NOT be wired in parallel & they both have to be configured to operate slightly differently.

I'll try to get back tonight if no one has helped before then.

 

[breezer]

i cant say for your bell box, you should wire the +ves and ringer terminals in paralel.
the first (lets say front) bell box also gets a -ve from the panel
the front bell box -ve return now becomes the -ve supply for the rear bell box (you just connect it in the panel with a choc bloc) the back bell now has +ve, -ve ringer and ringer. its tamper return now goes into the panel tamper return terminal.

That is how it used to be done with bells.

how ever, most modern bell boxes the tamper is either switchable or electronic, either way it limits the current on the tamper return, so you can't do as above.

what you can do is wire the back bell box tamper return to supply a relay in the panel, and use the relay contacts to break the tamper return from the from bell box

you can also wire the microswitches direct, but most sirens for economy its either built onto the pcb are out of the question


SAB TMP TO Return i called it a tamper return
Bell Hold- TO Hold-
Bell- TO TG- i called it a ringer
Bell+ TO Hold+

 

[tim_s_uk]

Thanks for the quick replies. I'm not wiring this for a couple of weeks, just planning now.

If the rear bell box gets its negative supply (Hold-) from the tamper return of the front bell box, then taking the lid off the front bell box will trigger the rear bell box on its internal battery (AFAIK). This would happen even if the alarm wasn't set, and the control panel won't be able to cancel the alarm.

The tamper switch is not surface mount, it has three wires going to the PCB. The common is connected to negative (Hold-). When the lid is closed the switch connects -ve to the tamper return (and nothing else). When the lid is open the switch connects -ve to to the circuitry via an internal/external jumper.

The solution I'm currently thinking of is to disconnect the tamper switch common and connect this to the unused screw terminal. With the internal/external jumper in the external position then the switch simply connects between the unused terminal and the tamper return terminal. I can then use two wires in six core cable to bring the tamper state back to the control panel, where I can wire them in series between -ve and bell box tamper (SAB TMP).

 

[breezer]

your statement about the front bell setting off the back bell is quite right.

that is how they are supposed to be. The only way you can guarntee the inside panel being able to stop the bells is to make a bell your self with no external battery.

By design all modern bells are either sam or scb- they have their own battery should the cable be cut it starts and there is nothing the panel can do about it.

however modern bells now have a timer in the bell so the most it should ring for is 20 mins.

 

[tim_s_uk]

Thanks for describing how two bell boxes are normally wired up. I'm happy for the bell box to start on its own if the wire is cut, but I would like to be able to silence them both if I open a bell box cover or if the tamper switch becomes unreliable. Rewiring the -ve side of the tamper switch back to the control panel should allow me to do this.

 

[breezer]

no it wont.

 

[tim_s_uk]

I wasn't very clear. I meant to write:
Rewiring the -ve side of the tamper switch back to the control panel will allow me to connect both tamper switches in series (at the CP):
(Click on images for full size)


Moving the tamper switch wire looks like this (Voltex bell box):

 

[breezer]

still wont work.

your modified drawing shows the _ve of both bells connected diretly to the panel

 

[Europlex]

You are making a very simple (but really the wrong thing to do, but your choice) job complicated and difficult.

What do you want to do(?) stop the boxes making a noise to suit yourself.

As you like soldering irons, what makes the noise, the sounder in each box, break one of the feeds to each sounder through a double pole switch back at the panel.

Connect both boxes as per your first drawing (each back to the panel on its own cable) using 8core cable, one pair from each sounder doing the job. - JOB DONE

Don't forget to re do your soldering back to the original.

 

[Europlex]

To explain a little further, the way you are trying to do it there are situations that can occur that will still sound the sounder/s - my way will not.

Don't forget to use some sort of indication that they are off, usually create a fault on a spare circuit so the alarm can't be switched on with the sounders switched off.

 

[breezer]

i agree with your first point, in that what is the point anyway.

but unless its a key switch (remember them?) anyone could turn it off, also if the cable is severed the sounders wont work which sort of defaets the point of an sab

 

[Europlex]

Yea, well, I know that, you know that, but ................., there ya go.

.... and as Breezer said, a key switch is best for a little! safety.

There's only so much hand holding.

 

[breezer]

perhaps you and I should buy him some ear defenders?

 

[Europlex]

I wish the Emoticons worked correctly


"BIG SMILE"