EHU + Inverter Through Same Sockets

[wolfy240]

Hi All,

For clarity i have scoured for threads already but can't 100% find the answer i'm looking for.

Setup:
EHU from bonnet runs under driver and to rear of van where the breaker & charger units will go.
Leisure battery on passenger side, fused & run to drivers side where i plan to put the inverter 300W(cont) Photonic Universe. the inverter has an earth nut.
Also on the drivers side will be the heater pipe coming up through the floor and out the back panel of the seat.

Ideally i'd like to plumb the inverter into the mains line i've already run to the rear using a crossover switch.

From what i can find, i believe i need to do the following:
Put a plug with and RCD from the inverter to the switch
split the line and put the crossover switch between the two.

What i can't find any real confirmation on is whether the inverter needs to be grounded?
WHen on the EHU switch the breaker will be earthed to the chassis and to the EHU ground spike outside.
But when inverter is selected surely this would also be grounded via the breaker?

Also is there going to be some serious heat issues with this and the victron MPPT being in the same bay as the outlet? I Guess i could insulate it to reduce a build up.

Worst case i'll just run the inverter floating but then i've got another socket and i wanted to try and keep everything neat and tidy.

Looking at @Deaky @Dellmassive etc.

Thanks in Advance.

 

[Dellmassive]

It you want to use the same van 240v sockets for EHU and inverter, you need to fit a transfer switch..

Or fit an inverter with an integral transfer switch.... Like the Renogy inverter.

This is to eliminate the chance of connecting the EHU and inverter supply together .. . Which is not good.


....

Inverter only - needs no chassis earth.

External EHU - must have a chassis earth.


Again as transfer switch can deal with the earth switching .

 

[Dellmassive]

Another option is to use seperate outlets for EHU.

And inverter.

So they are isolated from each other.

 

[Dellmassive]

More info here.

https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf

.

 

[Qnapper]

Not sure this is what you want, but none the less..... I wanted my 240volt sockets all live when using inverter off grid. I also wanted to use sockets whilst on EHU whilst on campsite. I found this little box of tricks listed below top do the job. It works be sensing if the EHU cable is connected to the RCD box and switches off supply from inverter to sockets, but if EHU drops out within seconds Inverter takes over. Hope this helps you.



LINK: MPC 1000 Switching Station, switching station inverter mains priority circuit control - H-Tronic Ladetechnik

I think you can buy them on amazom

 

[wolfy240]

It you want to use the same van 240v sockets for EHU and inverter, you need to fit a transfer switch..

Or fit an inverter with an integral transfer switch.... Like the Renogy inverter.

This is to eliminate the chance of connecting the EHU and inverter supply together .. . Which is not good.


....

Inverter only needs no chassis earth.

External EHU must have a chassis earth.


Again as transfer switch can deal with the earth switching .

Thanks @Dellmassive,
My intention would be to use something like this, nice and simple and cheap with the switch under the seat and also so I can turn the inverter on and off at the switch.
https://amzn.eu/d/clzPyQ2

Attach a plug to the inverter and wire it into the crossover switch. Then have that go direct to the RCO as below.

Another option is to use seperate outlets for EHU.

And inverter.

So they are isolated from each other.

I'm already running enough cable to the rear of the van i didnt want to add another thick mains cable.

i.e. do i need to run another ground from the inverter ground pin (presumably for the 240v side) or do i just run the 3 pin cable from the inverter to the switch then let it continue its run around the system using the ground from the RCD?

Not sure this is what you want, but none the less..... I wanted my 240volt sockets all live when using inverter off grid. I also wanted to use sockets whilst on EHU whilst on campsite. I found this little box of tricks listed below top do the job. It works be sensing if the EHU cable is connected to the RCD box and switches off supply from inverter to sockets, but if EHU drops out within seconds Inverter takes over. Hope this helps you.
View attachment 184074

LINK: MPC 1000 Switching Station, switching station inverter mains priority circuit control - H-Tronic Ladetechnik

I think you can buy them on amazom

@Qnapper I did see your thread on this but it still didnt quite answer my question/confusion.

 

[Qnapper]

wolfy240, Diagram added to my post and I think it is what you need. No switch needed​

i.e. do i need to run another ground from the inverter ground pin (presumably for the 240v side) or do i just run the 3 pin cable from the inverter to the switch then let it continue its run around the system using the ground from the RCD?

I have run a 3 pin cable from inverter to the box above, it does the rest. In your case, the switch may do the same thing. Because it's electrics I wanted to be safe and not use a switch I could forget about left in wrong setting.

 

[wolfy240]

wolfy240, Diagram added to my post and I think it is what you need. No switch needed​

Thanks, I was hoping not to have to have another bulky box in the already limited space but i believe it does provide good understanding of the required wiring.

 

[Dellmassive]

this looks like a manual transfer switch . . .


+++++++++++++++++++++++




+++++++++++++++++++++


+++

assuming your inverter had a floating earth / neatral connection, then you could wire like this?

 

[Qnapper]

Thanks, I was hoping not to have to have another bulky box in the already limited space but i believe it does provide good understanding of the required wiring.

Granted it's another box to fit, but it is a case of "fit and forget"

 

[Dellmassive]

that box is a very nice bit ok kit . . .

it was available here:

https://amzn.to/3ikrUsD

and not to be confused with the MPC1000 drum machine . . . .






++++++++++


as @Qnapper pointed out,


you can find it on the German site: MPC 1000 Umschaltstation - H-Tronic Ladetechnik


but its out of stock atm . . .




.



+++++++++++++



FWIW - John & Mandy used one in 2020.

 

[Dellmassive]

 

[Qnapper]

I didn’t know John&Mandy used one. I fitted it 18 months ago and works a treat with my 180

View attachment 184154View attachment 184156View attachment 184155View attachment 184157

Looks more or less (less room for me) the same setup. Fitted 18 months ago and as I have stated "fit and forget" Always get asked by other campers when we are out and about how I have live sockets making coffee in an aire. The only thing different to Dellmassive's is I have colour coded my cables using yellow to the RCD box, blue from inverter and white to power source

 

[Dellmassive]

the interesting thing is they show a common PE (protective earth)

but dont mention about any Inverter PE/Ground bonding.






...............................



but Victron do mention about PE/Ground bonding:

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

....


Edit.

 

[Qnapper]

the interesting thing is the show a common PE (protective earth)

but dont mention about any Inverter PE/Ground bonding.


View attachment 184170



...............................



but Victron do mention about PE/Ground bonding:

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

View attachment 184171

Not had a problem to date.......

 

[wolfy240]

out of interest @Qnapper do you leave your inverter switched on i.e. on the physical unit? or do you turn it on when you set off on a trip knowing the box of magic will kick in? Id expect an inverter would still draw a moderate amount even without being used, if nothing else just by dissipating heat. maybe @Dellmassive could provide some wisdom here.

Otherwise thanks gents, i now know what i need to do!

 

[Dellmassive]

Indeed, inverters use power on standby. Some more than others. And the higher power they are the more standby power they use.

In my case I switch the inverter on when it's needed via the remote on/off switch.

As an example it's off when driving about, then while camping when we arrive and setup it's switched on for the weekend....then switched off again for the pack down and drive home. (So not switched on/off 10 times a day during a camp out)

 

[wolfy240]

Indeed, inverters use power on standby. Some more than others. And the higher power they are the more standby power they use.

In my case I switch the inverter on when it's needed via the remote on/off switch.

As an example it's off when driving about, then while camping when we arrive and setup it's switched on for the weekend....then switched off again for the pack down and drive home. (So not switched on/off 10 times a day during a camp out)

Makes sense! Cheers

 

[Dellmassive]

Yeh. But it depends on your power source running the inverter.

Have you got enough power to run the inverter for the time needed?

We run a Roamer 230ah lithium battery, on a Renogy 1000w inverter, and recharge from a 50A Renogy dc-dc charger, and have 400w mobile solar during summer.

 

[Samro]

Not sure this is what you want, but none the less..... I wanted my 240volt sockets all live when using inverter off grid. I also wanted to use sockets whilst on EHU whilst on campsite. I found this little box of tricks listed below top do the job. It works be sensing if the EHU cable is connected to the RCD box and switches off supply from inverter to sockets, but if EHU drops out within seconds Inverter takes over. Hope this helps you.
View attachment 184074
View attachment 184079

LINK: MPC 1000 Switching Station, switching station inverter mains priority circuit control - H-Tronic Ladetechnik

I think you can buy them on amazom

Great link.
For £60 I shall buy one to replace my solution:
I had fitted one of these in a suitable housing which allows me mechanically to switch between EHU and Inverter, but your linked switch is a much more elegant solution:
https://amzn.eu/d/8ugEV3q

I had contemplated getting one of these before but at over £200 the cost is a bit rich!

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