Accenta Gen4 - Siren not working

22 Jan 2007
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United Kingdom
Having had an omnicron 7000 with 30 year old technology I decided to Installed a Accenta gen4 alarm, plus a remote keypad. Labeled all the wires off the old alarm and transfered to the accenta.

Im no expert at alarms, but thought id give it a go. All works well, the pir, door contacts etc, except the alarm siren. Ive Measured the out put between the bell + and Bell - on test and its stays at 3.5v, whether the bell test is on or off. If i remove the wire going to the bell+ then the siren will go off and the leds on the siren are working too so it must be getting the power, so what could be wrong ? also if i power down and disconnect the battery the siren will also go off.

I thought by running thru the alarm test, on the rkp bell and switching it from on to off and vv, this would result in a change of voltage between the + and -, the same theory applied to the strobe + and - does register 13.5 volts rather than 3.5. I've also checked I have no bell delay set and am mystified what to next, would most appreciate any ideas or further test i can do to get this working
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Bell pos and neg should equal 13vdc approx.
Bell pos and trigger in alarm the same.

Check for shorts on bell cable,
Thanks for that, but its only showing 3.5v not 13v between Bell+ and Bell- regardsless of whether the bell wire, whether the alarm is being switched between on and off on the test outputs of the engineer program mode.

However as mentioned earlier the strobe output on the board for example registers 0v when not set 13v when the strobe alarm test is done. Before using my metre i used a test 12v bulb between the + and - on the strobe connections and it will light up, yet on the siren it does n't. If the output of the bell+ or - is screwed could i not wire the siren to the strobe instead which is outputing 13v, as i have no strobe and it could feed the siren ?
You could, but if it trips the strobe latches. Unless your sounder has an auto cut off it will ring until a code is entered.
Against noise laws as they stand. 15 mins is the timer required now.
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Alarm, thanks and good point, would n't be too popular with my neighbours !!

So how I troubleshoot this further using the info i supplied. I cant reaqlly check the bell wire as its routed under floorboards, joists etc. However it was working upto the replace of control panels, 4 wires, 2 to the (+) (-) of the bell and 2 to the SCB.

However that aside, my simple bulb test of putting it across the + and - of the bell terminals should light up should it not, when the bell alarm test is switched to on, this works for the strobe test and lights up.

Why would the voltage be at 3.5v ?
should when i remove the wire from the +bell, the alarm go off, it does,
is there anything else i can test, can i test anything by removing the 2 SCB wires ?
ANything else i can test ?
Get to both ends of the cable and test with a meter for shorts.

Bell + and bell neg- should have 13vdc

Bell trig and Bell + nothing until output tested.

Only 4 cores = not enough really. So use + and - , trig and tr-.
Linking the strobe to the bell trigger.

What sounder is it and is it SCB or SAB. You have the manual?
Thanks and Yes i have the manua,l read the enginers guide, thats how i set it all up. As mentioned previously i cant test the siren wire, but it was working fine on the old system, which would suggest its not at fault. Also i should be able to test the outputs withput a bell wirte, using a 12v metre / lightbulb, which is a lot less noisy for the neighbours too !!

I have four wires coming into the pcb for the bell and scb, say for arguments sake i had muddled the wires up, and cant get to the bell box wire, how would identity what each wire does, is there a logical way of connecting them on a trial by error method ?

Testing 1 connector at a time so far reveals

Remove the bell+ siren goes off
remove the bell - no siren

using a simple 12v bulb on the connectors on the board ) which bypasses any potential bell wire issue, should the bell- and bell+ give 13v when the alrm is tested ?or is it the bell+ and one of the scb connectors ?

And why am i getting 3.5 volts on the bell+ -
Bell -, you sure thats not Bell Trigger your looking at?
Your not reading the terminals correctly!

Forget SCB , just forget it, its a term used for sounders.

T = tamper return, if working / fitted should be 13vdc.
D = a constant 13vdc
B = Bell trigegr only active in Alarm 13vdc
A = a constant negative ie, D and A = 13vdc
-st = Strobe trigger.

All voltgaes are nominal.

You need to read the manual correctly.
Ive read the manual properly, what you've told me is on page 9 of the engineers guide. And it refers to the bell + - connection on the board as i stated. Thats the easy bit

The difficulty here is was having 4 wires coming into the board and not knowing for sure how to connect them in the correct sequence to the tadb, given the info ive already posted i had hoped for a simple laymans guide to this, dont worry Ill work it out myself spending more time trying to explain in detail what the problem is than actually fixing it

The diagram is there.

Hold off and triggers.
Your not being able to identify the cables or test both ends is the only issue here.

You state bell + and - as a test point, that bell - is the TRIGGER not a constant supply.

I can talk you thru another method, got a bag of fuses?

But do as you say, saves me repeating myself.
funny you say that i just ordered 10 1 amp and 10 1.5 amp 20mm glassfuses will arrive later this week, am happy to work through a plan with you. this alarm talk, hold off and triggers does nt mean much to me i just transposed from the old panel to the new, and maybe the four wires hot mislabled.

On the plus side all 5 zones are setup and have 2 programs set up which work a treat, however only the internal sounder on rkp works, which is not much of a deterrent ! hence my need for a plan !

So if you had 4 wires coming into the board, not sure what ones to connect and no access to the siren or siren wiring, whats your plan !
Find two cores, any two.
Put one onto a hard pos another onto a hard neg.
That is a constant voltage, not a switched. So use the pir supply as you cannot work out trigger or a hard neg.
If the bell rings / sounds the pos is just that, the neg will go to the trigger (B). Keep swapping until the bell rings.
Now put one of the remaining onto a hard neg (A) and then remove it or the hard pos. That then should be the power to the bell.
You already know the strobe trigger.

Now you have a working bell, albeit without a tamper return. for that you need another core.

Cannot get it any more basic.

Another reason for marking all cables and terminations when doing swap outs unless you are very used to it.

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