Minimalist EHU MCB Install Help.

[T6VanLife]

I am currently at the planning stage of installing and EHU point inside the van, I am more than happy to work with 12v Dc all day but my knowledge runs out at 240V and I need to be absolutely certain it will work and be safe.
I am looking to Install the most basic set up I can get away with, as all I need is a 240V socket inside the van to charge my Powerstation easily. I am currently using one of these: https://www.amazon.co.uk/Vango-Voltaic-Power-Socket-Supply/dp/B07CHNCXLH
It works fine but its a bit of a faf ! I would much prefer a HU socket on the outside of the van and a standard 240v socket inside something like this:

Site EHU Point ---240v---> External Van Socket ---240v---> MCB ---240v---> Internal Outlet 240v.

My main concern is what type of MCB do I need ? I was looking at this model here: Standard AC Mains Consumer Unit With 1 x Double Pole MCB + RCD
And will it need to be grounded to the vehicle ? if so it will be mounted between the passenger side rear wheel arch and the tailgate pillar, so what would it be best to ground it to ?

 

[Dellmassive]

That's the one I used....

Dellmassive`s Camper Van Adventure

I can wholeheartedly recommend the diesel heater, they really do warm the whole van up really quickly. And it's handy not just when camping. Picking someone up/waiting around for someone with it's cold and don't want to sit there with the engine running for heat? Stick on the diesel heater...

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[T6 Syd]

I asked a similar themed question looking at the same end use really. A socket outlet for charging a power station. The mcb in the consumer unit protects where a fault occurs between the mcb and the socket(s) (and any fixed equipment but it doesn't sound like you will have any of that). It doesn't react to a fault between the EHU and the consumer unit/mcb/rcd. You have a, often short, length of cable in your van from the vehicle hook up point to the consumer unit. That, and the whole system downstream of the consumer unit, should be protected by the site EHU supply protection, an mcb and hopefully an rcd.

In my case, I'm looking at putting in a socket outlet with integral rcd. That keeps the rcd protection but not the mcb. The system downstream of the socket will be protected by the plug fuse, potentially slightly slower acting than an mcb but not by much that is likely to matter. I'll have a slightly longer length of cable inside the van that is protected only by the site EHU protection, but that wiring is behind the wall and inaccessible to people. That set-up means no consumer unit to fit in.

An alternative, avoiding the consumer unit in the van, would be to build the consumer unit into a waterproof box at the vehicle end of the EHU lead.

 

[T6VanLife]

Perfect Dell ! it was my first choice as its nice and compact. will that MCB need to have a ground wire run to a point on the vehicle ?

 

[T6VanLife]

Ok @T6 Syd so if I have understood this right you don't have an actual MCB in the van ?
Just an Inline RCD between the Site EHU and the External Socket on the van ? and no protection between the vans External Socket and the Internal 240v Outlet ?

I did actually consider this but wasn't sure if it would be safe enough ?

 

[T6 Syd]

I haven't completed it yet, but yes I'll be relying on the site EHU protection up to the connection to the back of my socket outlet, instead of to the inlet to a consumer unit. Not an in-line rcd as such, but a socket outlet with integral rcd - such as you often get at an external power outlet for a garden/shed.

As far as the mcb provision goes, what rating would you choose if it is to protect the wiring inside the van, between the consumer unit and the socket? Less than the site EHU protection, which may be 6, 10 or 16A? That will determine what you can plug into it and have it work.

I'm not a qualified auto-electrician, or domestic electrician, so my view on safety is my view not definitive.

 

[Stay Frosty]

If you want to go slightly more maximalist, on the off chance you might want to run additional 230 vac then you could fit a small garage consumers unit with an RCD incomer and say a 16A and 6A mcb or two RCBOs and a double pole incoming isolator, again a 6A and 16A, no point going any larger as the site supply is normally a 16A blue skt.
Screwfix and Toolstation have a decent choice.

 

[Dellmassive]

Perfect Dell ! it was my first choice as its nice and compact. will that MCB need to have a ground wire run to a point on the vehicle ?

If you plan on connecting up external 240v from the Grid into the van.....

Then yes the van chassis need to be PE Bonded.

I used the seat base as a connection.

(If the sockets are fed from a floating source(non grid), ie Inverter, ecoflow, generator etc... then no PE chassis bind needed.)

More info

240v consumer unit earthing

I just found this on the interweb...... To comply with BS7671 sect 721 any PERMANENT 240 volt installation in a vehicle (including caravans and motorhomes etc) should have the incoming mains supply earth bonded to the vehicle chassis. It also worth noting that any metal gas pipes should also be...

www.t6forum.com

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Dellmassive`s Camper Van Adventure

I can wholeheartedly recommend the diesel heater, they really do warm the whole van up really quickly. And it's handy not just when camping. Picking someone up/waiting around for someone with it's cold and don't want to sit there with the engine running for heat? Stick on the diesel heater...

www.t6forum.com

.