Door bell cable

[Alexphd1]

What size of cable for a hard wired doorbell with longish runs longest run 20m, 3 runs so 60m in total. 

Has anybody a wiring diagram for two chime (front and back door) 3x chime box set up, happy with a external transformer. 

Edited February 19, 2021 by Alexphd1

[markc]

Door bell is so low powered (almost zero current) that cable size is almost irrelevant. For multiples its will be easier to run a 2-core to each call point back to a central controller/chime unit.

If you are going for long runs then a 12v circuit would be better than the very low voltage units

[TonyT]

It would be easier to use alarm wire, it’s stranded takes 1amp per core up to 50 volt, multiple cores etc

less prone to break like bell wire.

[TonyT]

Just run 1 cable from each device back to a central joint box that will let you configure and alter set up easily without taking devices off walls etc.

 

[Temp]

Perhaps look at a stranded CAT network cable?

[Temp]

2 hours ago, Alexphd1 said:

Has anybody a wiring diagram for two chime (front and back door) 3x chime box set up, happy with a external transformer. 

 

Presumably you want each button to sound a different chime so you know which door to go to, and the three chime boxes are for coverage in different parts of the house?

 

Quick google found this range can do that..

https://doorchimesuk.co.uk/catalog/product_info.php?products_id=629

 

That model supports lots of different wiring options including mains and built in transformers. The circuit below is just one possibility based on their option B using an external transformer and chimes in parallel.

 

You would run two core cables for the push buttons and three core to the chimes all to a central location like the CU where the transformer and a junction box is located. You might consider running extra cores to the pushbuttons as spares or future use. 

 

https://doorchimesuk.co.uk/pdf/CROMA_230.pdf

 

It says each chime box needs 12V at 0.5A so I'd use something like a 12V AC 2A transformer.

 

With more time it might be possible to eliminate the external transformer using one of the other wiring options.