Using Bell wire for 24VDC to power wall mounted tablet

Talk Electrician Forum

Help Support Talk Electrician Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

bazza2000

New member
Joined
Jan 1, 2022
Messages
4
Reaction score
0
Hi,

I have a redundant door bell in my hall. I want to install an tablet with wall mount directly underneath it and wondered if it was okay to use the bell wire (assuming its 24VAC) to carry 24VDC which will then be converted behind the tablet using a 24VDC to 5VDC buck converter to power the USB port on the tablet.

In addition, the current bell transformer at the CU it positioned outside of the enclosure I'm assuming so as not to mix Band I and Band II electrics. Would it be okay to fit a 240VAC to 24VDC transformer in the CU and ensure that the bell wire was additionally sheathed with 240v rated insulation?

And finally, the reason for going with 24v was to ensure no voltage drop over the approximate 10m distance to the tablet. Is there a better option still using the bell wire.

Thanks.
 
Personally I consider bell wire utter rubbish, even for wiring bells. Far better and not much larger or more expensive is speaker cable. Available from very small to quite large it has flexible stranded cores and better, stronger insulation and polarity markings.
 
Answer question 1 : As long as - an ELV (extra low voltage) device or circuit in which the electrical potential between conductor or electrical conductor and earth (ground) does not exceed 50 V AC or 120 V DC (ripple free)You should be fine with that voltage.

Answer question 2 : same as above, won't make much difference provided you keep it somewhat separated in and through the cu.

Happy installing.
 
I am reminded of a late Victorian house I bought some 40 years ago. Previously had been a HMO. There was an attic and 1 of the rooms had become a sort of wash room a crude bathroom. There was a double 13 amp socket over a sink and I could see it was crudely installed. On investigation the socket was supplied from a ring socket the other side of the room via bell wire which had been crudely carved into the plaster and then plastered over with a white filler. Goodness knows the purpose but being close to a mirror deduced was used for a shaver. Surprised bell wire was intact.
 
Top