Wiring a coffee shop on a bicycle !

[total1]

Hi all,

I'm a domestic electrician and was asked to do a job I'm unfamiliar with as follows :- 

A client has a trike (3 wheeler bike) with a large box on the front which is a mobile coffee serving unit.

It is to be static alongside a shops alleyway and I was asked to get power to it. The shop is supplying  the power

which was an outdoor socket fed by a dedicated circuit off a 32a RCBO and wired as a mini ring using x2 2.5 T&E.

My suggestion was to put a commando female wall mounted socket onto the wall next to the double socket

and on the trike and make an 'extension' lead using 4mm outdoor flex and male commando ends. Wire into the double 

socket and then as they want a couple of double sockets inside the trike box I'd use 2 lengths of 2.5 T&E connected to the 

female commando socket to make a tiny ring.

Another electrician has told them that this would be very dangerous. Can someone explain to me where I've gone wrong ?

Many thanks and try not to slate me too much.

 

[binky]

seen entire burger vans on similar set-ups and can't think of any issues with what you propose to do. Just be wary of the metal frame of the bicycle - I would suggest double insulated everything. 

 

[Sharpend]

Don’t think a lead with two male ends is a good idea? What should happen if the bike end became unplugged and Martha’s little boy picked up the plug and opened the cap being the nosey git he is, live pins await him? 
 

 

[Geoff1946]

What is the total load of the bike? 

Comparing it to a caravan, (which I'm familiar with), the difference is that there is another RCD within the van and the supply earth connection is bonded to the metal structure of the van. 

I can't immediately decide whether this is just a precaution against the van being plugged into a non-rcd source, or if it is additional protection.

 

[total1]

Thanks Binky

Hi Sharpend, thanks also, didn't think of that but I didn't realize you could get the wall mounted commando sockets it either (male or female), the ones I saw were female for the wall mount

and male for the plug.

HI Geoff1946

At the moment a couple of 13amp items (coffee machine and grinder) but they will shortly be getting a coffee machine that requires a 32amp supply

 

[Sharpend]

Forgive me, but doesn’t it defeat the object of being a mobile coffee shop if you have to site next to the same shop for a power supply? 

 

[Geoff1946]

Forgive me, but doesn’t it defeat the object of being a mobile coffee shop if you have to site next to the same shop for a power supply? 

Commando outlets are quite common around shopping centres and similar places, which may be a consideration in deciding whether there should be on-board rcd  and perhaps overload protection.

 

[Sharpend]

Commando outlets are quite common around shopping centres and similar places, which may be a consideration in deciding whether there should be on-board rcd  and perhaps overload protection.

I’m aware of this, most used for kids rides or pop up stands etc but a bike in an alleyway next to a shop suggests it’s on the street? So why? Seems a lot of hassle for a coffee, and now he wants provision for a larger supply. 

 

[Andy™]

a lead with a plug each end is more commonly known as a widow maker. if your still struggling to figure out whats wrong with it, go make one, plug it and and touch the live end. im sure youll soon figure it out. if youre lucky. i did one do a live demonstation for an 'electrician' after he wouldnt figure out why i failed a catering trailer he wired. despite  refusing to touch the live pins to confirm 'its safe' he still didnt see a problem with the setup...

and just for those exact situations, you can get surface mounted inlets to use with a normal extension with  plug one end and socket on the other...

youll also need section 717

and why bother running 2x 2.5 T&E. you do know rings dont apply here, dont you?

 

[kerching]

:BadIdea:

 

[boltonsparky]

Keep it simple, forget this ring and widow maker setup. Whatever you need in this box install and connect to the appropriate sized appliance inlet on the trike (16a or 32a) same as you would on a motorhome, catering truck, ambulance etc. Make them a standard cable (not a widow maker) h07rnf is the usual cable in either 16a or 32a flavour so they can plug into the wall mounted socket and connect up the trike.

Earthing the frame of the trike needs looking at/risk assesing depending on the construction of this "box", you could potentially be creating a more dangerous situation by earthing the frame.

 

[total1]

So what you're saying is make it a permanently fixed connection at the trike which plugs into the outlet on the shop, which eliminates the potential to get a shock off the live ends of the lead when it's been plugged in

 

[total1]

Hi Sharpend, the shop supplying the power for the coffer trike isn't owned by the client and isn't a coffee shop.

 

[apprentice87]

So what you're saying is make it a permanently fixed connection at the trike which plugs into the outlet on the shop, which eliminates the potential to get a shock off the live ends of the lead when it's been plugged in

You need an appliance inlet to go on the bike.. It is like a wall mounted PLUG NOT NOT NOT a wall mounted SOCKET [think about it]

Then there is earthing.. Think tncs and why caravans are not to be earthed in this manner..

john..

 

[total1]

Hi apprentice87, yeah I get what you mean, thanks. makes sense now

 

[phil d]

16A appliance inlet, also available with a cover

 

[Sidney]

Wire it up using a standard BS1363 plug. Also supply a short extension that has both 16 and 32 amp commando plugs to allow for variation in supplies.

Similar to this set up:

 

[total1]

Thanks guys for your help 

 

[Doc Hudson]

Never really understood the concept that sockets must always be wired as rings? Are some electricians scared of radials?

Doc H.

 

[Geoff1946]

I thought the end requirement is for 32 amps?  

HI Geoff1946

At the moment a couple of 13amp items (coffee machine and grinder) but they will shortly be getting a coffee machine that requires a 32amp supply