Interconnected smoke alarm - troubleshooting

[Neptune]

Intrigued to hear about possible causes for the IC failure on all but 1 of the detectors. Also, the new detectors are on the same wiring and currently working.

 

[Mikegh]

Intrigued to hear about possible causes for the IC failure on all but 1 of the detectors. Also, the new detectors are on the same wiring and currently working.

Not really following the thread but I've seen interconnect failure a couple of times

Caused it once myself by crossing the wiring and blew the heads , lesson learned

Have also seen it in an installation i was working in, wired but not working

 

[brianmoooore]

Near the beginning of this thread is a pic of the wiring to a head, showing that the wiring colour conventionally used for the interconnect and the neutral have been swapped around. I suspect that at some point a damaged base has been replaced by an electrician who connected the new one conventionally before realising his mistake after powering up. Corrected his wiring, and then walked swiftly away.

 

[Neptune]

But wouldn't that have blown all the IC's? Surprised that one of the device was okay and also the new devices are fine. Why have they not immediately blown?

 

[brianmoooore]

The one good one is probably the one that was being replaced, and hadn't been slid in place when the damage occurred, or it was the first base which has T&E and 3&E.

 

[DPG]

Intrigued to hear about possible causes for the IC failure on all but 1 of the detectors. Also, the new detectors are on the same wiring and currently working.

Has someone been in and performed an insulation resistance test on them at 500V?

 

[Mikegh]

Ya I only made the mistake once and it blew every connected head

Wss religious after that about checking base wiring prior to inserting heads

 

[Simon47]

Near the beginning of this thread is a pic of the wiring to a head, showing that the wiring colour conventionally used for the interconnect and the neutral have been swapped around. I suspect that at some point a damaged base has been replaced by an electrician who connected the new one conventionally before realising his mistake after powering up. Corrected his wiring, and then walked swiftly away.

This one ?

View attachment 91104

It strikes me that there's an indication of sub-standard design in these then. Given that such wiring errors are not exactly unforeseeable, you'd think they'd design the system to cope with it - it is possible to do.

 

[Mikegh]

This one ?

It strikes me that there's an indication of sub-standard design in these then. Given that such wiring errors are not exactly unforeseeable, you'd think they'd design the system to cope with it - it is possible to do.

You mean design the heads to cope with wiring errors ?

Is this a common issue or does it occur with other brands.Think it was EI in both cases I seen

 

[Simon47]

Yeah, design the heads so they'll survive common errors. Lets face it, who's never made a wiring error - ever - in their careers ?

 

[Neptune]

Has someone been in and performed an insulation resistance test on them at 500V?

Not that I am aware of

 

[Mikegh]

Not that I am aware of

Hmm ,.this thread has been going on a while now

I'm sure it's been mentioned that you have to prove the base wiring. IR , interconnect , polarity etc.