fire alarm

[connordev]

Hey all.
I recently 2nd fixed a conventional fire alarm system. I wouldnt be that familiar with them to be honest. It all worked fine anyway, apart from the last sounder on the 2nd zone. I have my EOL resister in the circuit and the panel is not showing any faults. The sounder is "ringing" very low when tested. I`ve changed it twice now and it is doing exactly the same thing. Can anyone shed any light?

 

[telectrix]

set the panel into "fire", measure the volts across the + and - at the sounder. you should get 24v. if not, then there is a poor connection before the sounder or you are trying to pull too much from the panel. if you have 24v " on alarm, the it's the sounder. some have dip switches for different tones. take sounder off and put 24v across it from the panel batteries and see if it sounds right then.

 

[telectrix]

or, perish the thought. you have connected the sounder incorrectly.

 

[The Finch]

some have a volume pot that can be adjusted but this is not normally touched, as mentioned above there are also dip switches or jumpers on some sounders but again if supplied as a new kit shouldnt need to be touched

 

[accordfire]

Hey all.
I recently 2nd fixed a conventional fire alarm system. I wouldnt be that familiar with them to be honest. It all worked fine anyway, apart from the last sounder on the 2nd zone. I have my EOL resister in the circuit and the panel is not showing any faults. The sounder is "ringing" very low when tested. I`ve changed it twice now and it is doing exactly the same thing. Can anyone shed any light?

Number of possible reasons.....

How many sounders do you have on the circuit - volt drop is the most likely reason for low sounder output, as it's usually proportional to input.

On which note, how much current are you drawing from the panel in alarm in total - is it within the allowance the panel gives - you'd be surprised how many times we get called out to other jobs only to find that there's a million and one devices on the system, all trying to run from a barely 1.5A supply on the panel - which is also trying to feed the panel.

Another possible cause is damage on the cable between the second to last and last sounder on that zone - contributing to increased resistance/voltage drop - which may not show up on many cheaper conventional panels as they have quite wide tolerances for end of line value.

Final point - some electronic sounders can use more current when set to certain tones than when set to others (not just between normal and loud settings).