V2L Test. 7kW output...

[Purclewan]

If you place an electrode in the ground and electricity is passed into that electrode during a fault it creates an Earth potential rise (EPR) in the ground, if there is another electrode within the EPR/earth zone for that electrode, some of that fault current will travel through that electrode and associated cable connected.

The DNO earthing system is referred to as a global earthing system when in a built up area, essentially the amount of copper in the ground the DNO has is that great that you cannot escape it, so when you island and you don't have a correctly designed earth unless you are in the middle of nowhere and a considerable distance from a DNO substation, you will also be within the Earthing zone of the DNO.

And if part of that network is being worked on your single rod and fault could endanger anyone working on the DNO network as an unintentional back feed.

Edit: that's why you have to make sure you have enough copper in the ground and a correctly undertaken earthing study to ensure that next to no fault current goes into the DNO earthing system by making yours the path of least resistance, this is again only applicable when islanding this is why loss of mains is mandatory on G98/99 inverters so they can't island.

Your connection to the DNO network has to be compliant with the Electricity Safety, Quality and Continuity Regulations (ESQCR), part of that places an obligation on the end user to not breach the requirements of those regulations through there actions or inactions.

If you are completely off grid you have a legal obligation to not cause harm to anyone else through your actions or inactions.

As the DNO is there already incumbent you have to ensure you don't cause injury or damage to any person, property or livestock through what you do or don't.

Thanks Ayoull,

As someone who is exploring off-grid and grid backup systems for my own use, I suppose what I am getting at is the difficulty in getting a comprehensive and straight answer to earthing issues surrounding particularly this subject.

Although I have worked in the computer industry for the last 30 years I did qualify as an Electronics engineer, keep myself abreast of new developments and think I have a pretty good understanding of electrical systems. However, despite reading widely and studying all the relevant regs I can find, nothing I see is clear cut and in fact in many instances can seem downright contradictory. It all seems to depend on who is doing the reading.

What seems to be the case is that once again Technology is running ahead of regulation. I want to ensure my installation is safe but getting straight answers is proving difficult with plenty of reasons why I can't do something but few practical suggestions on how I can. In fact typically what I read on the IET forums (for example) is several people (all engineers) will give several different opinions on the same earthing problem and quote different regs. All highly confusing.

What does seem to be a common thread are "real-world situations" and "common sense".

 

[Ayoull]

Thanks Ayoull,

As someone who is exploring off-grid and grid backup systems for my own use, I suppose what I am getting at is the difficulty in getting a comprehensive and straight answer to earthing issues surrounding particularly this subject.

Although I have worked in the computer industry for the last 30 years I did qualify as an Electronics engineer, keep myself abreast of new developments and think I have a pretty good understanding of electrical systems. However, despite reading widely and studying all the relevant regs I can find, nothing I see is clear cut and in fact in many instances can seem downright contradictory. It all seems to depend on who is doing the reading.

What seems to be the case is that once again Technology is running ahead of regulation. I want to ensure my installation is safe but getting straight answers is proving difficult with plenty of reasons why I can't do something but few practical suggestions on how I can. In fact typically what I read on the IET forums (for example) is several people (all engineers) will give several different opinions on the same earthing problem and quote different regs. All highly confusing.

What does seem to be a common thread are "real-world situations" and "common sense".

I think part of the problem is off-grid is becoming viable for general usage where as in the past it was larger systems where an earthing engineer would design all that side would liaise with the DNO to make sure there wasn't anything going to be impacted by what they are trying to achieve.

And the ENA who come up with DNO codes of best practice and engineering recommendations hasn't had time to catch up. I think V2L came out of left field as alot of what DNOs have looked at a V2H and V2G in both of which they isolate at loss of mains.

 

[t5t]

Has anyone looked at the efficiency of using V2L compared to grid power. There must be efficiency losses both charging the battery, and converting DC back to AC for V2L? I was also wondering if using V2L would help to keep the battery warm due to internal resistance?

 

[Greenie]

Has anyone looked at the efficiency of using V2L compared to grid power. There must be efficiency losses both charging the battery, and converting DC back to AC for V2L? I was also wondering if using V2L would help to keep the battery warm due to internal resistance?

Not done v2l but I can say that my solar PV home inverter/batteries lose about 10% of electricity when squirting into the batteries from the grid and 10% when sending to my home.

 

[siteguru]

So your home storage charging system has ~90% charge efficiency.

 

[Greenie]

So your home storage charging system has ~90% charge efficiency.

Yep, somewhere around that. And about 90% discharge efficiency. They don't tell you that when they're selling you a solar PV system! Still works out way cheaper to charge at night then discharge during the day.

 

[amdmad]

Do I need to buy a special kettle when using the discharge adapters , and do I need a RCD extension lead for when we go camping,as some campsites charge extra for electricity?

 

[Ian Key]

Do I need to buy a special kettle when using the discharge adapters , and do I need a RCD extension lead for when we go camping,as some campsites charge extra for electricity?

You can buy a V2L lead into which you can plug in an ordinary kettle. The official max output is 3kW but some have achieved more. Just make sure the cable/adaptor is for a MG4 otherwise it might have the wrong resistor fitted which tells the car it's a discharge cable.

 

[skynett]

Anyone tried the Load Capacity on the SR version of this Car?

 

[Lovemyev]

You can buy a V2L lead into which you can plug in an ordinary kettle. The official max output is 3kW but some have achieved more. Just make sure the cable/adaptor is for a MG4 otherwise it might have the wrong resistor fitted which tells the car it's a discharge cable.

We have a 0.5 litre capacity travel kettle that is only ratted at 1 Kw.
Not too large to carry around and enough capacity for a little over two mugs of tea / coffee etc and is WELL inside the carrying load of the V2L cable.
Very affordable and can be used on 110v - 240 volts of course.

 

[DeMille]

Both myself and my neighbour have our MG4s wired to our household consumer units to run the house directly from V2L.

We were told the MG4 output only 2.2Kw,

Our old Kia EV6 output 3.5Kw

Today we decided to push them as far as we could..

With a meter on the input, we ran 2x 600w IR Heating Panels f+ 1x400w IR Heating panel for 1.6kw

At the same time boiling a 2.5Kw Kettle and running a 2Kw Induction Cooker Hob

General Load of Lights TVs and Computers plus other ancillaries 800w


Gave 6.9 Kw output. ran that stable with no issues, threw on a toaster and it kicked out and shut down, started up again as soon as the toaster load was removed.

So it seems the MG4 is happy with a 7Kw output. Much much better than expected. Was expecting no more 3.5 max

Also let me say this test was done with a proper type 2 V2L adaptor wired up with 6mm cable and direct back to the house with 6mm armoured cable. Please dont try and pull more than a couple of Kw from those Ebay Plug in type2 to3 pin adaptors.

This moment one is able to buy LFP batteries for +- 150$/KW inclusive BMS and Eu delivery. 60 Kw storage would be +- 9000$ + 1000$ for the inverter = worth 10000$ or the diff between a normal car and an EV. If one makes the same calculation using a cheap Tesla home battery +- 800$/KW One has an MG4 long range for free, even an Ionic 5. Having solar panels one must have very good reasons for buying an EV not having V2l witch by the way excludes all Eu manufacturars and Tesla.

 

[Mg4forluxury]

Hello MG Lovers,
I am new to this forum and was looking for supporters regarding the possibilities of connecting my MG4 as a home battery on wheels to "part" of my home. My electrical installation consists of 3 phase, each of which is fused to the GRID with a 25 A / 230V AC main fuse. The entire electrical installation of the house is divided into large consumers such as "hot water instantaneous water heater", induction hob, 2 air conditioning units, etc.
1 phase is specially equipped for: refrigerator, freezer, lighting and a number of primary sockets throughout the house.
This phase is "entirely" disconnected from the GRID from the moment the MG4 is connected.
This is done by an Automatic Transfer Switch (ATS) which switches the "Neutral and Life".
I use a Zappi to load the MG4 Trophy (In the Netherlands MG4 Luxury.
A second Type 2 plug is connected to the ATS. All earthed sockets remain connected to the "standard" earthing of the house and are not switched. That way there is no "floating grounding"
It is a test set-up and I would appreciate further developing this concept of "optimally safe".
There are of course a number of disadvantages associated with this device.
There must be a manual switch between the Zappi (charging) and the V2L home situation.

 

[deanhalllincoln]

Interesting thread and something I have been working on with my MG4. So this is what I have found so far hope it helps someone:-
a) when connecting the V2L connector (home made one) and selecting discharging in the car I get 226v between live and neutral.
b) measuring L to E voltage I get 186v
c) measuring N to E voltage I get 28v (will be an Inverter output but a behaving like a centre tapped transformer output)
d) the earth is not connected to the chassis of the car (no continuity)
e) there is no connection to ground from the earth output from the car (obviously as only 4 rubber tyres between the car and ground)
f) I can connect the earth from the car to an earth rod to give a ground connection. however this does not connect neutral to the earth/ground that is needed to operate a an RCD.
g) I have connected the live, neutral and earth from the car V2L to my consumer unit and powered my entire house from the car. tested all appliances PC, tv, oven, boiler etc… and all worked.
h) testing the connections in the house when powered from V2L provides some unacceptable results. As the earth is not connected to the neutral at the source sockets can show as reverse polarity, missing earth, RCD’s do not operate under fault conditions.
I) Connecting the earth to an earth rod at the source does not help And I get the same results.
J) the problem is that the neutral needs to be bonded to the earth at source just like a normal house TN-C-S system. This would provide the right return paths via the earth and fix the system to earth and not have a floating system.
k) I have tried connecting earth and neutral together at the output of the V2L connector to simulate a TN-C-S system and the car shuts down the discharge as it sees the connection as a fault.

So I can power my house from the V2L connector but not safely with the right level of protection I would want. The car prevents me creating a safe system as it shuts down the discharge if earth is connected to neutral.

I got this far if anyone else can come up with a safe way of doing this I’m all ears.

Dean

 

[Mg4forluxury]

Hello Deanhallincoln

Thanks for the quick response. It's good to see that more people are looking for a solution to use V2L to power your entire house (or part of it) from the MG4. So far I have only received negative advice with the answer "don't do it".
I think my situation is slightly different from yours. I have only connected/disconnected part of the electrical installation of my home.
Actually, I followed the example of "Tom's manshed". Tom, however, uses a loose cable to a fixed switch, which switches his "manshed" between his MG4 and the GRID.

In my case I have therefore only isolated a number of wall sockets "with earth" and the lighting of almost my entire house to one phase. The earthing of the relevant wall sockets is carried out via the house installation. This home installation has its own. certified" earth stake.
The MG4 is also connected via the same ground. The "specially made" green V2L plug of the isolated group, which plugs into the MG4 (resistance 470 ohms) also has the earth wire, which is directly connected to the earth of the house installation.
Now I can follow the train of thought that the GFCI is "off".
Is it an option to add an extra RCD for the V2L circuit.

I haven't connected my MG4 yet. I will pick this up at the dealer on May 10 (tomorrow).

I would like to hear from anyone who reads this and is looking for a suitable V2L solution with the same thought, whether it is possible to create a "working" and "safe" solution.
I have included a situation drawing, to provide insight into the entire wiring diagram

 

[Rolfe]

I quite fancy having the potential to do this during power cuts, but it doesn't look very feasible at the moment. An extension cable to allow the freezer to be plugged in might be possible.

 

[deanhalllincoln]

Hi Mg4forluxury

Regardless if you are powering the whole house or part of the house the earthing arrangement in the Uk (I assume Netherlands is similar) would not be adaquate. The problem is the car provides 220v but its a "floating" supply. This means its not referenced to earth and Neutal in the normal way a standard electrical system in a house would be referenced.

A house electrical system has a connection diectly between earth and neutral and this fixes one side (the neutral) of the supply to earth. This earth/neutral connection is vital to ensure devices such as an RCD would operate correctly.

e.g. when my house is supplied via the mains and the earth is tied to the neutral the RCD will operate correct as expected. When I supply the house from the car the RCD dose not operate correctly this is because its a flaoting supply and the earth is not being connected to neutral.

In the Uk we refer to this type of earthing arrangment as an IT system and its only viable for one appliance at a time. See this youtube video that explains this arrangment and its drawbacks.



To get around these issues we need to connect the earth to the neural at the output of the car but as I mentioned above the car sees this as a fault and shuts down the supply.

 

[Tig170]

if you've already got solar, why dont you DC couple (using appropriate DC chargers from the V2L part (230v AC) of the MG4) in parallel matched (with appropriate MC4 splitters ) to your solar panel voltages, and put it through your solar AC to DC invertor - that way your not touching anything on a governance / legislative side - I've tried this and it works, but to be honest if you can get in some more solar panels - Ive just paid £150 per panel for 4 x 405W Logic black panels - which yields around an extra 5Kw of power, each day for the house, at this current time.

 

[Mg4forluxury]

Hi Dean,

Thanks for the explanation. As I understand it now, it is actually impossible to use the V2l output as a backup for any grounded device. An earthed power strip will therefore always remain floating, while there is plenty of experimentation with the MG ZS, MG4, MG5 Ioniq 5 and EV6 VL application i.c.m. several household appliances. In my house (1976) most of the wall sockets are ungrounded. Of course, the WCDs in the kitchen, bathroom and attic (Central heating) are earthed. In the living room, the TV and lighting run without grounding. In my case I would only like to run the fridge and freezer on the V2L.
Actually, I have created an isolated group of animals, as it were, coupled with the MG4, like the example of Tom's V2L solution.


My situation is similar to Ton's. I switch off the entire phase of the GRID and connect it, as it were, to the MG4 with the Type 2 V2L connection. Do I understand correctly that the solution created by Tom (and many others on the internet) is NOT justified ??

Is there no single solution to use the V2L safely?

 

[Mg4forluxury]

if you've already got solar, why dont you DC couple (using appropriate DC chargers from the V2L part (230v AC) of the MG4) in parallel matched (with appropriate MC4 splitters ) to your solar panel voltages, and put it through your solar AC to DC invertor - that way your not touching anything on a governance / legislative side - I've tried this and it works, but to be honest if you can get in some more solar panels - Ive just paid £150 per panel for 4 x 405W Logic black panels - which yields around an extra 5Kw of power, each day for the house, at this current time.

Hello
That also sounds interesting.
Iki have two Omnik inverters hanging (2500w and 3000 W). these are both connected to a phase. I have a total of 6000 watts peak in solar panels.
If I understand correctly you see a solution in connecting the V2L of the MG4 to the DC input of one of the inverters.
That in itself sounds logical.
It would be nice if you could use this one of the inverters after sunset to provide the home with energy from the MG4.
It would be nice if you could make a picture of this with the necessary parts to realize this solution.
I already have the V2L MG4 230V solution in my home.
This is by means of 3x 4 mm2 to the ATS in my technical room assembled. Here are also the two soral inverters.

 

[Tig170]

Please see attached - we've done both AC & DC coupling - currently we're in off grid mode - and awating DNO commisioning given the new rules in Sept 2022 (for the UK - for our system - ENA Type Test Register

Photos attached of our decomisioned system (but the MG4 does charge the ESS battery system albeit at a selected 1KW only. )