USB amps and cables

Torchy

Full Member

Messages
226
Hi there,
In my motorhome, I have one double USB output running the usual 5 volts from the leisure batteries.
I went out and invested in two more of these double 5 volt USB sockets. The same design that simply replaces a normal 240 volt 3 Pin UK socket.
My question is, can I just simply wire each of the additional USB up to the already installed USB Socket?
I will be blanking off the old 240v wiring and running completely new 5v wire for the USB's
 

wildebus

Full Member

Messages
3,395
Hi there,
In my motorhome, I have one double USB output running the usual 5 volts from the leisure batteries.
I went out and invested in two more of these double 5 volt USB sockets. The same design that simply replaces a normal 240 volt 3 Pin UK socket.
My question is, can I just simply wire each of the additional USB up to the already installed USB Socket?
I will be blanking off the old 240v wiring and running completely new 5v wire for the USB's
almost certainly (assuming superthin wiring has not been used)

PS - the USB sockets may provide 5V out, but you will be running the usual 12 volts from the Leisure Batteries ;) (the USB devices will do the conversion)
 

Lemut

Full Member

Messages
5
Hi Torchy, I've got a feeling that you may have an amperage issue if the new sockets simply piggy back off the existing. If the new unit has its own 12v to 5v stepdown unit great, just need to check the circuit wiring size (as per Wildebus) is OK for the load.
 

wildebus

Full Member

Messages
3,395
One thing that should definitely NOT be done is change the supply fuse for this circuit to a larger one because you have extra sockets fitted. The fuse is to protect the cable and is appropriate to its gauge.
 

Okta

Full Member

Messages
557
Perhaps I don’t understand the question but the original sockets take 12V DC and step it down to 5V. The new sockets take 230V AC and step it down to 5V. They don’t sound interchangeable to me.
 

wildebus

Full Member

Messages
3,395
Perhaps I don’t understand the question but the original sockets take 12V DC and step it down to 5V. The new sockets take 230V AC and step it down to 5V. They don’t sound interchangeable to me.
I think he is removing the 230V sockets to give him the holes to fit the USB sockets i.e. "I will be blanking off the old 240v wiring".

If you have a modular system like the CBE one, while the wiring will change, the same physical fitting space can be repurposed to fit any of around 50+ different devices without making any more holes (y)
 

Torchy

Full Member

Messages
226
I think he is removing the 230V sockets to give him the holes to fit the USB sockets i.e. "I will be blanking off the old 240v wiring".

If you have a modular system like the CBE one, while the wiring will change, the same physical fitting space can be repurposed to fit any of around 50+ different devices without making any more holes (y)
Thanks Wildebus.
Firstly there is no way I would ever change the fuse rating, that would be pure stupidity, but there again thanks for reminding everyone as someone out there could.
I have Berker fittings inside my MH (Elddis got something right), so I can interchange sockets for anything I wish to without making brand new holes.
I am changing two of my 240v outlets for 5v USB's. The old 240v wires will be carefully capped off (in-case I should want to revert back - can't understand why I would want to).
I've seen what wire is used (Yellow and White), yellow probably the 5v feed (have to use a voltmeter to check), not sure about the white wire.
Its very straight forward piggybacking onto the main feed, but remembering, I can't use all three sockets at once otherwise "overload" will occur.
I will try to take separate feeds from the main 12v source to each new socket but this depends on many factors.
I think the most difficult part of this job is routing the cable.
 

wildebus

Full Member

Messages
3,395
The Berker is a nice flexible system as well. I tried that, but was too used to the CBE way :)

Ref the colours, I think white will be ground, especially if Eldiss use a Sargent based electrics setup - Sargent use White with an orange tracer for their -ve connections.
As a (possible) aside, US RV wiring also use White for -ve. Something to watch out for if fitting US sourced 12V kit, for example the MaxxAir Fan has a Black and a White wire for the supply. White is -ve, Black is +ve!

I don't think there is any problem in adding sockets for added flexibilty as long as you (and anyone else) remembers they may be current limited. I added 3 extra 12V sockets in my van, all piggybacked from a single 12V outlet. This was for a very specific purpose and the total load on those three sockets will be 50W (4A) - and circuit is a 10A circuit so I am happy with that - IF I were to use the outlets all as 120W outputs, the fuse will go and that is fine, as that is not what they are for :)
 
Top