How many volts/amps are allowed outside?

Hi, I plan to make some things that will be used outside in the UK. Obviously 230V mains is only allowed if its properly waterproofed but im not so sure about lower voltages. Ive seen those cheap x-mas lights that are suitable for outdoors even tho they arnt remotely waterproof but they are allowed as long as the transformer is inside.

How many volts/amps are allowed by law without requiring special waterproof wires/enclosures? My project at the moment will use 24V 7A DC. It will be in a plastic box that i will try to seal as well as possible. Will that be legal to use/sell in the UK?

Another concern is the sockets. I plan to use a standard DC socket (like on a laptop etc) and some mini-din sockets for data. Will they be alright at such a low voltage or would i need to use special ones?

Here in the United States that kind of regulations are ruled by "The National Electrical Code", NEC. Most electrical boxes outside need to be waterproof. There are many companies that sell waterproof enclosures.
I have no idea what type of electrical regulations you have in the UK. I would recommend you to look for the NEC equivalent in the UK. There you should find everything.

Robert

Ive googled for a UK version but i can only find the US one. If we have something like that then i assume its called something different but google isnt giving me any leads

You have to look for European Standards. If I googled it correctly it is called CENELEC. Also, if you know any electrical engineer that does power design, he should know.

Robert

Hi
In the Uk outside Xmas lights are 24v ac and several amps. Portable tools transformers are 110v ac centre tapped, 55v to earth 10 20 30 amp output etc. providing you use a ready made 230v/ 24v dc isolating transformer then you should be O.K.?

Tom