Interconnected smoke alarm - troubleshooting

[Mikegh]

You can probably verify the interconnect with a wander lead with supply off

Check it's not connected to the alarms supply too

If you can't get any to interconnect test a couple of complete units on the ground

Not sure if the interconnects can give trouble

I came across an installation with a good few alarms and the same issue but wasn't fixing it at the time

I learnt my lesson once anyway that you can blow them all if you're sloppy with the wiring

 

[Neptune]

I found it odd that none of the detectors were going off together - when I tested. I had expected most to chime simultaneously and perhaps the odd one not too as there may be a loose cable.

 

[freddo]

Are you keeping the test button pressed long enough? The interconnected ones wont start sounding for 5 or so seconds after the first one. Hold the test button in for 10 seconds to check. Aico are good alarms..

 

[suffolkspark]

With the power off you need to pop the little connection cover off to check they've actually been wired with the right cable. May not even have an interconnect core.

 

[littlespark]

Have you lot been up all night staring at your alarms waiting for a red flash?

go round each one, press and hold test for 5 to 10 seconds….. you will be able to tell if any are interconnected, some are interconnected or none.

For the bases without detectors, take one from a base you know is working and swap it into the vacant base….

if the detectors are daisy chained, the first one will have a twin and earth for power, (brown and blue with sleeved earth wire) and a three core and earth going out to the next base. (brown, black, grey with sleeved earth)
The other bases will be 2 x 3 cores- one in, one out…. And the last one will be just one 3 core.

 

[brianmoooore]

The other bases will be 2 x 3 cores- one in, one out…. And the last one will be just one 3 core.

Hopefully it will be 3&E. Not unknown for T&E to supply power to the first one, and the cpc of more T&E to be used as the trigger wire for the rest.

 

[littlespark]

Hopefully it will be 3&E. Not unknown for T&E to supply power to the first one, and the cpc of more T&E to be used as the trigger wire for the rest.

True. I maybe should have mentioned “3 core and earth” throughout the post

 

[loz2754]

Hopefully it will be 3&E. Not unknown for T&E to supply power to the first one, and the cpc of more T&E to be used as the trigger wire for the rest.

From post number 1:

They have a 3 core and earth cable for the interconnect.

 

[nicebutdim]

Missing heads shouldn't have any impact on hardwired interconnection as remaining heads will still communicate with each other.

 

[Mike Johnson]

@Neptune. As we have found out different series of Aico alarms have different operational parameters, what alarms do you have? Product Range - Aico - https://www.aico.co.uk/product-range/

 

[Neptune]

@Neptune. As we have found out different series of Aico alarms have different operational parameters, what alarms do you have? Product Range - Aico - https://www.aico.co.uk/product-range/

I will check and come back to you. Thanks for your help

 

[Mikegh]

Missing heads shouldn't have any impact on hardwired interconnection as remaining heads will still communicate with each other.

They should and should be relatively straightforward to establish what's going on here

I'd tend toward removing all heads first and work from there , sort out the interconnect and get 2 heads fully operational

 

[nicebutdim]

They should and should be relatively straightforward to establish what's going on here

I'd tend toward removing all heads first and work from there , sort out the interconnect and get 2 heads fully operational

Assuming the system is correctly wired and originally worked, what issues might occur beyond connections in each base or damage to fixed wiring?

 

[Mikegh]

I'd be very cautious about working on the wiring with heads in place after i blew all the heads in an installation once

I wouldnt be totally amazed if the interconnect isn't working on the heads either although it's much more likely to be the wiring

 

[Mikegh]

Assuming the system is correctly wired and originally worked, what issues might occur beyond connections in each base or damage to fixed wiring?

Assuming the system is correctly wired and originally worked, what issues might occur beyond connections in each base or damage to fixed wiring?

I suppose that's what I was wondering did the interconnect originally work

I blew all the EI/aico alarms in a new installation once, foolishly mixing supply and interconnect

Another time I saw an installation with where the interconnect didn't work at all and the supply /interconnect was looped from one to the next, so I would expect it to be operational to some extent

So I was keeping an open mind on this

 

[Mike Johnson]

Good reason not to use T&E for the interconnect, Aico recommend min 0.75mm perhaps boot-laced multi strand would be preferable, personally I have not used cable interconnect preferring the radio link, much easier.

 

[Neptune]

UPDATE: I finally got around to taking a look at this today and wanted to share my finings and plead for further help please.

• Firstly, none of them had the green or red light on display
• Some of the detectors beeped upon using the test button and some did not. None of them caused other alarms to beep at the same time.
• I then removed the heads and started testing across live and neutral using my 2 pole tester. None of them had mains power
• I noticed that all of them had 2 sets of 3 core and earth cables - except one which had 3 sets of 3 core and earth and another alarm that had 1 set of 3 core and earth and 1 set of 2 core and earth.
• That last detector was the power supply and again, had no power when tested with the 2 pole tester
• I then traced this cable in the loft and quickly found a Fused Spur that was switched off! I have now marked this appropriately
• 
• Once this was switched on, all base units had power
• I slid the heads back in and they all had the green light apart from two
• 
• these two heads were unlit when tested in other bases too. I concluded that they were faulty and needed replacing

However, none of the alarms are causing any of the others to beep. I tested each one individually and held down the test button for over 10 seconds. Only that alarm beeped. They've all got an interconnect cable and the same colour is being use throughout and this system was working when first installed a few years ago.


All the heads are Ei141rc apart from the kitchen heat sensor. This is EI144RC.


1 of the EI141RC has this sticker and if I recall correctly was installed more recently. Still the same model as the others?

And here is the heat detector in the kitchen:


I am at a a loss and hoping that you can shed some light on this. Thanks again.

 

[westward10]

You need to carry out some continuity tests to verify all conductors.

 

[Mike Johnson]

From the manual available here: Ei144RC Instructions - Aico - https://www.aico.co.uk/downloads/ei144rc-instructions/

"Interconnected Alarms only - Test the first unit by pressing the button for 10 seconds. All the units should alarm within 10 seconds of the first horn sounding. The red light on the first unit only will flash about once a second. On releasing the button the local Alarm will stop sounding immediately and the remote Alarms will stop sounding approximately 3 seconds later (if testing using RF interconnection this could take slightly longer). This will verify that the interconnect is working. Check all the other units similarly."

If this does not work then suspect continuity issues with the interconnect as suggested above.

 

[Neptune]

You need to carry out some continuity tests to verify all conductors.

Can you elaborate on this please. Not a trade leccy!
Do you mean continuity on the interconnect cable? Even if a few of the links were broken (which I have no reason to believe) I expected the remaining devices to work in tandem. It would be very unlikely that all of them have broken interconnects?

Note that mains power is carried across to all the devices.