Alarms - Mains Wired, Interconnected

[nero44]

If it's okay with you lads, I would like to continue on my thread and ask some more questions...

Bank Holiday weekend allowed me to do some more progress on this, but it was a pain. I managed to drill through the joist and place a cable, but no chance to get it into the void.

This is the top floor, so I paused this part for now. I did manage to install a heat alarm in my cellar and ran a cable up into the floor of my first floor, where I was able to install another smoke alarm on the ceiling to the ground floor.

I then tried to fish a cable from first floor up to the second floor and it was a proper pain. I tried with my cable rod from second floor down and from first floor up, but there was a blockage in the bottom third of the void. So I decided to cut an access hole too see what's going on. Got my trusty multitool and successfully severed two cables tripping the fuse with a bang..

Upon opening the hole a bit more I think I understand what's going on and why I was not able to get my cable rod through. The void is completely filled up with plaster debris, but I think there is also a diagonal joist blocking the way. This is pretty much opposite of this! So whoever wired this house just took all the cables outside the void, ran them over and ONTOP of the laths, and just covered it with a plasterboard. Further down the cables go back inside the void again and come though into the floor normally. And of course I multi-tooled exactly where the cables are closest pressed against the plasterboard.

Anyway...damage done! Opened the hole a bit more and temporarily reconnected with some inline Wago's.


My question is, how should go about fixing this? The good news is that I am now able to run my fire alarm cable as I found the blockage. It appears all other cables are fine, but I cannot just push these wages back in, and both cables are part of a longer circuit, so I cannot just pull out the entire cable and replace with a fresh one. The only options I can think of:

1. Backbox with blanking plate and wagos inside (looks ugly)
2. Maintenance free JB inside (not sure if fits, might need to take out a lot of that debris)
3. install a single socket there as JB (don't really need a socket there, and also the other cable is a light circuit, so that would not solve the second severed cable)

Any other bright ideas?

 

[nero44]

Alright, I've decided to go with option two.

Frist, enlarge hole downwards and remove as much debris as possible. So that will give me some space inside the void. Remove some of the laths and push cables back inside the cleared void. I severed two cables, one ring and one 3core+cpc light circuit.

For the ring, I will use a quickwire 2-way splitter. I found this to be the most space saving MF solution. the 3core+cpc unfortunately I will need to use quite a large JB box (from Hager) to be sure its MF to BS 5722... most MF JBs can only carry 3 terminals....hopefully I can squeeze that in there somehow. Will probably post again once done to see what the best way is to patch up re-decorate the area... maybe a california patch...

 

[trojanhawrs]

I would just heatsink over one end, double ended crimps over each core, tape it all up and slide your sleeve over and shrink.

 

[nero44]

I would just heatsink over one end, double ended crimps over each core, tape it all up and slide your sleeve over and shrink.

Been thinking about this a bit more.... I do not have the right equipment to do heatshrink and crimping... I did buy this Hager JB, but it's huge! The box is as large as the entire opening. Even if I open up the hole a bit more and free up the void, it will still take up a lot of space and interfer/block/pinch the other cables. Ideally I want the cables to be running in the void as free as possible in case someone in the future gives them a tug from either above or from below. The problem is, that it's 3 core+cpc and there are no small MF JBs with 4 terminals.

So in the interest of safety, is there an argument to not use a MF classified box to make the connection less disruptive in the space given? I am not saying to use a taped up chocblock, but the 4 wago inlines (left cable) would perfectly fit into a wagobox light. But the wagobox light is only classified as MF, if used together with a mounting carrier, which secures the wagos to the box. This is only available for 3 terminals, but I require 4.

Any thoughts on this anyone?

 

[SimonH2]

Just my 2d worth.
Another vote for Aico.
I too prefer hardwired if possible, but you can mix & match with Aico. In the flat, I have two heads on one hardwired circuit, and a head and test switch hardwired on another. Two heads have radio modules which link the two circuits.
One annoyance is that with multi-function alarms, they differentiate the cause (e.g. CO is a different tone to Heat), and if radio linked, all the alarms will copy this. But when hard wired they don't.
Also, the radio modules cost nearly as much as the alarm heads - so can nearly double the cost of the hardware.

Another annoyance is that shortly after I fitted separate multi-sensor smoke and CO heads in the same room of our rental house - Aico brought out a combined unit. Trust me, having two heads going off, plus a third at the top of the open plan stairs is LOUD. The tenant's cats made a very speedy exit the first time she set them off with "steam" when opening the bathroom door

 

[nero44]

Finally had some time to work on this again. Cleared out a lot of the debris. Ended up not using the Hager, but instead a Wago with line for the 3-core and a quick wire for the 2.5m T&E. After pushing everything inside the void it actually looks quite decent.. no significant strains etc. I've already closed the box and plastered over it. Onto some more wiring!

 

[nero44]

Last post on this...

I finally managed to finish this project, and quite proud of my work. Installed 3 smoke alarms + 2 heat alarms (all Aico) over 4 floors, all interlinked and mains wired. Had to open up a small bit of wall in four different places and drill through 3 noggins that were in the way, but in the end it worked out and I managed run all the wires as I intended to. Was it worth it? To me yes, as this is my home and I wanted it done properly and I learned a lot in the process. Would I do it the same way if I was paid by the hour or doing this at someone else's place? Absolutely not!

Thanks to everyone who contributed on this. Now I get to fill out one of these aico fire alarm stickers myself and stick it to my CU

 

[ebee]

Well done.
Must admit I`ve done a few hardwired interlinked (Providing I could get them all on the same circuit) as a first preference and a few interlinked by wireless if they on differing circuits or to avoid a lot more disruption.

I admit that due to my age I have an ingrained unease about wireless and whilst I see the improvement in technology in wireless over many years I also noted the vulnerabilities of wireless with regard to intruder alarms from blocking and false alarms from early generations of products which has biased me.
Indeed a relative of mine a few years back found his caravan nicked off his drive despite having wireless CCTV and a wireless alarm which they jammed easy, don`t know what cheap kit he had but I had advised him to use a hardwired CCTV he had bought new and to modify an existing unused intruder alarm in situ but did he listen? which was easier for him to set up? which was easier to nick though?
I never uttered the words "I told you so!"

 

[bernardgreen]

I admit that due to my age I have an ingrained unease about wireless

I have the same unease after 50 years experience of the ( mis ) use of wireless.

 

[JohnW2]

I have the same unease after 50 years experience of the ( mis ) use of wireless.

That makes at least three of us, then.

It's not just a matter of 'paranoia' or 'dislike of change/the new-fangled' - there are some genuine issues, and some of them are likely to get worse as time goes on.