BAFFLING smoke alarm problem

[Octopus]

^^ not sure if I agree with this.

R1 + R2 followed by Rn + R2 at first alarm would be my next test

 

[Paul228]

Agreed Murdoch, but they post was becoming circular.

 

[Midwest]

Because us **** shovelers can do anything

Clearly not, although apparently I can give tips to plumbers on how to install a bath, so the mastic doesn't fail after a few months

 

[Rpa07]

Holding onto that one aren't you @Midwest - I had a chuckle when that conversation was going!

 

[davesparks]

I don't know but I once wired a 2way and fitted LED lamps that wouldn't go off completely and changed the lamps to another make and all was fine I have also heard of cables run together getting enough power in them to make an energy saver glow ! The folk were convinced they had a ghost maybe it was so unless it's something like that or to do with your battery's in your alarms but like you said better not to guess but not being able to see it makes it harder to picture things. Just trying to think out of the box as your convinced your wiring is right !

That is caused by capacitive coupling between conductors.

 

[davesparks]

I would disconnect at the lamp end and run a length of t&e and connect the smoke n heat off its own supply as a temporary measure, this will prove you haven done owt silly and will show if the heat n smoke are compatible.

How do you think an incompatibility of the alarms going to cause the problem the OP has? I honestly cannot think of any logical way it could be causing this and am intrigued to know.

 

[davesparks]

No but that was something that was on the cards tomorrow. Start with the simplest of things before I rip the place apart

Changing the lamps will only hide the problem at best, it won't solve it.
The best place to start is measuring voltages between all appropriate points in both switch positions and with one, two and no alarms installed, write the results down and you should be able to interpret the results to get to the answer.
If it all worked before you made the addition to the circuit then there is no need to rip the house apart, logically it must have been caused by the addition.

The most simple and logical possibility is that the alarms are connected between L and Sl instead of L and N. this is very easy to test so why not start there?

 

[westward10]

I agree even with different makes they tend to interact. This is irrelevant as to why the lights no longer function correctly.

 

[Octopus]

wonder if the OP's got any test kit?

 

[gutterball]

I had a similar problem a while back. The light was glowing whilst off. The alarms were wired into the live feed to the switch, so the switch return to the light was connected to the smokes neutral. when you removed one of the alarms the glow stopped.

 

[Wilko]

I had a similar problem a while back. The light was glowing whilst off. The alarms were wired into the live feed to the switch, so the switch return to the light was connected to the smokes neutral. when you removed one of the alarms the glow stopped.

Sorry, I'm lost ... little dwg?

 

[gutterball]

JB > sw > light ok so far?
feed for alarms joined to cable between jb and sw. so n of alarms between sw and light.

 

[gutterball]

sorry brain not working too much jack d last night. rose 3 plate, not JB.

 

[davesparks]

I had a similar problem a while back. The light was glowing whilst off. The alarms were wired into the live feed to the switch, so the switch return to the light was connected to the smokes neutral. when you removed one of the alarms the glow stopped.

Which is exactly the situation I've described above.

 

[Midwest]

And me sort of

 

[Brian Angell]

Check your 3 core interlink cable. You may have got the neutral or the switched (alarm) live in the wrong terminal at one of the heads.

 

[davesparks]

Check your 3 core interlink cable. You may have got the neutral or the switched (alarm) live in the wrong terminal at one of the heads.

How will that cause the light to partially illuminate when the switch is off?

 

[Dave OCD]

As previously stated I'm also certain that the cable used to feed the new alarms has been connected to a live and switched live return rather than L & N. It's the most logical and obvious explanation.

 

[Midwest]

As previously stated I'm also certain that the cable used to feed the new alarms has been connected to a live and switched live return rather than L & N. It's the most logical and obvious explanation.

I've been saying (and shed loads of others) having been saying something similar all along. Up to OP to report back and let us know the particular fault.

 

[westward10]

I expect he has the place in bits now.