Interconnected smoke alarm - troubleshooting

[Neptune]

Hi,

I have an aico alarm system which was mains powered and interconnected when installed 3 years ago. It's not been maintained and when I took a look recently, a couple of the detectors are missing. Only the ceiling plate is on the ceiling. Also, the interconnect isn't working. When I test any smoke detector, only that beeps and - none of the others.

I need to ensure that they are all still mains powered and restore the interconnection between them. They have a 3 core and earth cable for the interconnect.

I am pretty handy with electrics and own various tools including a fluke 2 pole tester.

I have 8 detectors. Can you please suggest a logical approach for this. Does the indicator on the detectors have any significance?

Look forward to receiving your advice. Thanks in advance.

 

[SparkySy]

I agree with @westward10 when you had the units heads removed did you just visually inspect them or did you give each wire in the interconnects a tug with some needle nose pliers? I have come across them before where the cable looks as if it's terminated properly but is not.
I would try the ones with three cables to them first.
While they are all down a long lead between them and continuity test is next on the list and just work through the circuit until you find the culprit!

I would definitely have a good look at the call point as well, is it one with a test function on it?
I take it it's not one of these?

Locate and Remote Control Test Switch Surface - 1529RC3 | Aico (EI1529RC)

 

[HappyHippyDad]

As @westward10 had said. You just need to test for continuity between the cables.
You're making it complicated. Keep it simple. You just simply test for continuity and slowly narrow down where the problem is depending on whether you do of don't have continuity between the conductors.

 

[Neptune]

This really is a process of elimination. What I would do is check all connections and then confirm conductor continuity.

Can I reliably check continuity with a wander lead and fluke 2 pole tester? It has the continuity function

 

[suffolkspark]

Can I reliably check continuity with a wander lead and fluke 2 pole tester? It has the continuity function

Probably as long as the tester is capable of working over a distance and isn't just a little multimeter type one which may not

 

[Neptune]

Sorry for the incessant questions. Just want to understand the situation before I carry out the necessary tests.
One thing I am still unclear on: if the interconnect cable is appropriately connected to some devices and the link is broken at others (loose connection or a short), would you still expect the devices that are connected to sound in tandem? Or does it require a complete circuit across all devices?

 

[Mikegh]

If you have say 7 and the interconnect is broken in the middle

3 on one side of the break will sound together, same on the other side

 

[Mike Johnson]

The alarms do know how many devise's you have connected, have you tried all your alarms to see if any of them sound in tandem.

 

[littlespark]

@Neptune. I dont know if its been suggested earlier, but where in the UK are you?
Maybe there's a forum member nearby could assist for a crate of beer.

An electrician will have the know-how to fault find in a logical manner, and will be much quicker than you just poking around.
Having reread the thread, this is a rental property? so i assume its empty at the moment, as you cant let it out without working fire detection.

 

[brianmoooore]

In an earlier post you said that at least two detectors are faulty.
Buy two new ones, take the two bases out of the boxes, and connect them together with three pieces of wire on the bench. Fit one of the new detectors to one of the bases and then fit each of your existing detectors, fitted with a good battery, to the other base in turn. Push the test buttons to check that each will trigger the other.

 

[Mike Johnson]

I suggested bench testing back on post 50, we seem to be going around in circles.

 

[Mikegh]

I suggested bench testing back on post 50, we seem to be going around in circles.

Me too in post 21

 

[Neptune]

In an earlier post you said that at least two detectors are faulty.
Buy two new ones, take the two bases out of the boxes, and connect them together with three pieces of wire on the bench. Fit one of the new detectors to one of the bases and then fit each of your existing detectors, fitted with a good battery, to the other base in turn. Push the test buttons to check that each will trigger the other.

got it! Thanks again

 

[Neptune]

I agree with @westward10 when you had the units heads removed did you just visually inspect them or did you give each wire in the interconnects a tug with some needle nose pliers? I have come across them before where the cable looks as if it's terminated properly but is not.
I would try the ones with three cables to them first.
While they are all down a long lead between them and continuity test is next on the list and just work through the circuit until you find the culprit!

I would definitely have a good look at the call point as well, is it one with a test function on it?
I take it it's not one of these?

Locate and Remote Control Test Switch Surface - 1529RC3 | Aico (EI1529RC)

It's this type of device:

Do you know if this takes a key or somehow doubles up as a testing point?

 

[westward10]

Is it that exact call point. That type you test by inserting a fork type key in the bottom and sliding the cover down.

 

[Neptune]

Is it that exact call point. That type you test by inserting a fork type key in the bottom and sliding the cover down.

It's not the exact one but i will post a picture of the one that I have. Thanks again.