ELV supply for tent camping.

broadgage:

A friend owns a farm and offers tent camping pitches as a sideline. 

They wish to provide a limited and safe ELV supply to such camping pitches, for lighting, charging of electronics, and other low power uses.


Does anyone see any flaw in my proposal which is as follows.


For each pitch provide a 13.8 volt DC supply, current limited to 8 amps, this obtained from a DC to DC converter contained in a locked enclosure. Output via 2 core heavy duty rubber sheathed flex terminated in a plastic box on which will be mounted 3 automotive type cigar lighter outlets. Small green LED pilot lamp to show that the supply is on. No overcurrent protection required as DC to DC converter is current limited. No means of  isolation provided at such a low voltage.

When not in use the trailing leads and the outlet boxes will be stored under some form of small shelter.

When in use, outlet box in users tent.

Cable size selected to give a minimum of 11 volts at full load.


10 camping pitches, 5 post mounted boxes, each containing two supplies.


"mains" input to these DC to DC converters to be 3 wire DC at 26/0/26 volts nominal, which could be up to to about 30 volts actual. Obtained from the main RE system at the farm buildings.

Distribution via 10mm twin with earth cable, overhead and well out of reach. Each post will also have a small amenity light to give low level area lighting.


The main 3 wire DC system has the center wire earthed. The CPC in the 10mm twin with earth cable will be used as a current carrying conductor, but only for the earthed center wire.

The 13.8 volt circuits derived from this system are isolated from earth.

What about some 240V sockets in lockable lockers for portable device charging? Most people will have a 240 V mains charger or U.S.B. charger.


Or one of these.....Outdoor Revolution Mobile Mains Power Unit USB 18M Cable | Winfields Outdoors

Z.

tattyinengland:

Yup I see a problem - 


We camp a lot and would expect to receive 230V at the pitch if we have asked for a pitch with electric hook up. 


Campers do not have 12V kit - caravners might do?

That was my first thought as well. Though the farmer could have a shop selling the required kit if there is not a local garage already selling it.

mapj1:

Do folk use  cigar lighter outlets much any more ? most cars are non smoking and most of the hand held electronics I have seen expects 5V, from the 'USB' type connector.

My new car has a cigar lighter socket in the boot. ?


There is another one between the front seats, but no ashtray; also USB sockets and wireless telephone charging.


The old one also had cigar lighter sockets fore and aft, but they were issued with actual cigar lighters and ashtrays. ?

RichardCS2:

Cigar lighter connectors are very nearly the worst possible connectors, being designed with a spring that actively tries to eject them from the socket. They have a nasty tendency to loose connection and need wiggling, they often run hot, etc. By all means provide some which campers can use for their own equipment, but I think I would be inclined to put something more reliable on the hired equipment.

Agreed. They also are of poor quality and rust really quickly internally.


Z.