Sterling 10 activation when system not armed

[Atko13]

Hi All,
I wonder if someone can help with some fault diagnosis on my alarm system?
I have a Pyronix Sterling 10 system with LCD keypad and Cequra external sounder, several PIRs and magnetic contacts. System is over 16 years old but has been extremely reliable. New panel battery fitted Nov 17.
Unfortunately the system went off on Christmas Day (yes, I know!) whilst we were watching the telly - it was not armed. It could not be silenced with the user or engineer codes and was showing the '!' (exclamation mark) fault symbol on the keypad. I switched off the mains power supply, opened the main control panel and disconnected the back up battery. This silenced the internal sounder but the external sounder continued until I opened it and disconnected the battery in it as well (bit tricky up a ladder in the dark half cut with a torch in my teeth!).
The only other thing I noticed was that the external sounder was making a sort of squealing sound, not the proper siren sound. However, when I powered down the control panel (and disconnected the battery) this squealing changed to the normal siren sound.
Anyway, my main question is what could have caused it to go off suddenly like this?
Obviously something has failed so I would like to try and identify what and would be grateful for your suggestions of what to look for and/or how to diagnose the problem.
I have looked through previous threads but have not been able to find anything relevant.
Hope you can help.
Many thanks.

 

[secureiam]

hmm,

cant be certain but here goes.

if the normal sound occurs at the bell box with the power from the panel disconnected it could be panel fault, bell fault or cable fault.

You can measure whats coming out of the panel to check that its behaving normally.
If you replace he bell box, think ahead as to what panel you may go for if you decide/ find its the panel that's gone, to try and make things easier later.

I am guessing that the issue is related to the 12v from the panel, or the circuit in the bell that handles the 12V coming in.

 

[Atko13]

Thanks secureiam.
I will try to measure the panel output at the weekend and check cable continuity. Hopefully that should eliminate the panel or sounder, or cable.
Funnily enough, I was thinking about replacing both anyway, simply due to their age. I was considering the Pyronix Euro Mini Prox and Deltabell E sounder as they look like nearly a straight swap for installation and wiring. Assuming I need to replace one/both, any idea if they are any good or if there are better options out there? I don't need anything fancy.
Many thanks

 

[scott1980]

The Euromini and Deltabell would be a good choice if you're considering an upgrade. The Sterling 10 was never a brilliant panel when it was new and the ones we have to look after at work haven't aged well. I went to one on Wednesday where the panel tamper switch had simply broken from its mounting peg of its own accord over the christmas period! Similarly to yours, this one didn't actually show the fault on the keypad, just an exclamation mark.

 

[Atko13]

Thanks scott1980, appreciate your comments. It's always good to have a recommendation.

 

[Atko13]

Managed to do a little investigation this afternoon and established the items below. To be honest, I was not sure which terminals to check for 12V panel output to the external sounder, or which for 12V input to the external sounder - not helped by having different coloured wires at the panel and sounder, clearly there are some joints somewhere. Anyway, here goes:
With all power off at control panel, full continuity achieved on tamper circuit for mags/PIRs.
Tested 2 fuses on main pcb - both ok.
Opened sounder, checked voltage from internal battery (approx 6V), reconnected the internal battery and refitted cover (heard a very short 'buzz' when tamper switch clicked shut as the cover screw was done up). No other noises, flashing LEDs or strobe.
Taped tamper switch closed on panel, reinstated mains power and system booted up ok. Reconnected battery. All ok except lcd keypad buttons didn't look fully illuminated but display screen was normal.
Carefully checked voltage from transformer to pcb - approx 17V.
Checked voltage and continuity on each zone connection. Zero volts on all except when PIRs activated which then showed 5V. Continuity ok on all.
Output from AUX terminals was approx 12V (PIR supplies).
Everything seemed ok (not expected!) so I thought I would try to set the alarm as usual. Unfortunately on doing so it went off with internal sounders (keypad and panel) sounding but the external sounder did nothing at all. I silenced it by entering the user code and it showed 'tamper' on the screen - assumed this must be a tamper at the sounder as detector tamper circuit had tested ok. Cleared this by entering the code again.
At this stage gut feel said it was the external sounder at fault as the panel seemed to be doing its job. I guess it could be a cable continuity problem to the sounder but to check that I would need to run another wire, as a return, which I don't have at the moment.
However, I thought I would see what happened when I untaped the panel tamper switch - expecting it to go off - but nothing!
I don't know if any of this helps with a diagnosis but would be interested in anyone's thoughts.
Currently thinking I will probably replace the panel, keypad and sounder unless anyone can pinpoint the problem based on my limited fault finding skills!
Thanks

 

[Atko13]

Forgot to say that continuity was lost on the tamper circuit when I opened/closed the panel tamper switch by hand so I know the tamper switch is working properly.

 

[secureiam]

sounds like you have been busy, if you get a new bell you could wire it up near the panel if it works okay you could swap it out for the current one?

its common enough to have joined cables, you could test for shorts and then test continuity by pairing up??
so you measure from panel end red up black down??? as long as you don't find a short on any of the cables???

 

[sparkymarka]

Link out tamper zone and bell tamper , now see if there is a fault ....

 

[Atko13]

Thanks very much for your suggestions both.
I may as well link out the tampers and see what happens.
Do you know which terminals to link out the bell tamper at the panel? I have wires connected to BT, BA and STB. So I assume its BT to BA? Terminals B- and B+ have nothing connected but I do have wires connected to terminals -SPK+ which I assume go to the external sounder as I have 5 wires connected to it.

 

[sparkymarka]

B- to BT

 

[Atko13]

Great, thanks very much! Will try it tomorrow.

 

[Atko13]

Followed your excellent advice and confirmed the external sounder is the problem! Can't thank you enough for the help!
One last question if I may, regarding the sounder connections.
I have checked cable continuity from panel to sounder and confirmed 3 wires which are the bell tamper, siren and strobe. However, at the sounder there are 5 wires connected, the additional 2 being supply hold off +ve and -ve. I cannot find the other ends of these wires at the panel so wonder what they are connected to. In the panel I have B- B+ terminals which have no wires connected at all.
Looking at various sounder wiring diagrams there are usually at least 5 connections to the panel so I am at a loss here! Can anyone shed any light on this?
If I swap to a different make of sounder I am worried I might need to run new wires or worse ie trace cables in the loft! If I stick with the same sounder I hope simply reconnecting the 5 wires will work.

 

[Atko13]

Should have said that the -SPK+ terminals in the panel are connected to a small speaker in the panel behind the PCB, not to the sounder as I thought.

 

[sparkymarka]

The supply for the bell maybe taken off or shared with ( landing pir ) ? At a guess , next step are your pirs lighting up ? If the pir supply fuse has blown then this could be your tamper issue on the bell