V2L Test. 7kW output...

[Stageshoot]

A standard 32A Type 2 lead uses 6mm2 so why not use one of those for the flexible part to connect to the car? Tethered leads can be picked up on eBay for under £50 if you look carefully, or you can cut up a Type 2 to Type 2. Just remember that you want the female end (that goes into the car - meaning you can't cut up a Type 1 to Type 2 lead which only has a male type 2) and you want one that you can unscrew to get in to change the value of the controlling resistor.

Thats what I am using

 

[deanhalllincoln]

Hi guys since reading this thread I have been thinking how I can create a similar setup for my house as the original poster using V2L to supply my entire house. Stageshoot appears to have a TT earring system where as I have a TNCS earthing system. My house is approx 25 years old and the consumer unit is a split type with main switch controling all circuits and a 30ma RCD protecting about half the circuits (sockets etc…).

installing a 100A change over switch in the tails from the meter to the consumer unit and an additional time delayed 100A RCD 100mA to protect the entire instalation is no problem. The earth wire from the car would be connected to the earth terminal in the changeover switch and hence to the main earthing terminal of the house at the cutout.

However, as I am on TNCS do I leave my main earthing conductor from the Consumer unit connected to the Neutral at the cutout? One one hand the TNCS combined neutral and Earth is a far better return path to earth where current would only flow in the event of a fault in my house. The fault current would be restricted to a maximum of 100mA and then the main RCD would trip. I suppose I could make the main RCD 30mA non time delayed and restrict fault currents even further.

Or

Do I convert the earthing system to a TT system and disconnect the house from the TNCS system at the cutout? This has the advantage that no fault currents would flow along the DNO’s neutral wire but the path to earth would be far higher resistance. Although it does provide protection against any PEN faults even though these are very rare.

Or

Do I leave the TNCS earthing connected and install an additional earthing rod to the main earthing terminal as an additional path to earth? there Is no reason why I cannot do this as many houses converted to TNCS leave the old main earth rods connected. Any fault current would naturally flow along the low resistance PEN conductor but in the event of a PEN fault there is an alternative path back to earth via the earth rod.

I did consider switching the main earth conductor in the changeover switch (would have to be 3 pole) so the installation switches between TNCS (when on main supply) to TT (when on car supply) but the cross sectional area of the main earthing conductor would not be maintained through the changeover switch.

I’m struggling to figure out the correct way to go here. I want to have the right fault protection in my house when connected to mains and don’t want to push current down the DNO’s cables if they has engineers working on them and think they are isolated.

Have I missed something anything that I would be considering?

any thoughts would be gratefully received.

Dean

 

[Stageshoot]

Another test today, after some adjustments to make sure entire run was 32amp cable

Been doing some more power tests on the MG4 V2L

So far have pushed it up to 30amps 7kw. run for2 hours now with no issues and no cutoffs.

Our V2L is wired back to the house via a proper 7kw Type 2 Lead (Converted to V2L) and a 32amp armoured cable. (Beware a lot of the cables sold are only 13amp ones).

Today we had

2x 1Kw IR Heater Panels
1x 3kw Induction Hob
1x 2.2kw Oven

+ Standard House Loads.

Flicking between 20 and 30 amps depending on load on hob etc.

Not pushing any higher as cable is only 32amp. But really proves the MG4 can chuck out 7kw for a prolonged period.

Really making this car a game changer for backup power, the EV6 shut off at 3.5kw so one major appliance and house load was its limit, the MG4 is making this just so easy.

 

[tsedge]

Another test today, after some adjustments to make sure entire run was 32amp cable

Been doing some more power tests on the MG4 V2L

So far have pushed it up to 30amps 7kw. run for2 hours now with no issues and no cutoffs.

Our V2L is wired back to the house via a proper 7kw Type 2 Lead (Converted to V2L) and a 32amp armoured cable. (Beware a lot of the cables sold are only 13amp ones).

Today we had

2x 1Kw IR Heater Panels
1x 3kw Induction Hob
1x 2.2kw Oven

+ Standard House Loads.

Flicking between 20 and 30 amps depending on load on hob etc.

Not pushing any higher as cable is only 32amp. But really proves the MG4 can chuck out 7kw for a prolonged period.

Really making this car a game changer for backup power, the EV6 shut off at 3.5kw so one major appliance and house load was its limit, the MG4 is making this just so easy.

View attachment 13110

Presumably it can do 7kW because that’s the capacity of the cable/charger in the car anyway.

Do you have an SR or LR? Just wondering if a LR would achieve 11kW with a 3 phase cable? (apologies if you have already covered this).

Edit: though obviously 3 phase output wouldn’t be that useful for most!

 

[siteguru]

Devices in cars may not be equal capacity in both directions.

 

[tsedge]

Devices in cars may not be equal capacity in both directions.

I don’t see why it wouldn’t, but you may be right.

 

[siteguru]

Charging the car uses a Converter; V2L uses an Inverter - separate devices.

 

[Stageshoot]

Presumably it can do 7kW because that’s the capacity of the cable/charger in the car anyway.

Do you have an SR or LR? Just wondering if a LR would achieve 11kW with a 3 phase cable? (apologies if you have already covered this).

The output is not related to the input

The EV6 was capped at 3.5 output despite having a higher input than the MG4

Have Trophy so bigger battery with 11kw 3 phase

But the output on the NG4 same as the EV6 is only single phase

 

[tsedge]

Charging the car uses a Converter; V2L uses an Inverter - separate devices.

Not necessarily - there are designs that can do both, though I acknowledge they may be separate devices in the MG4, I don’t know.

 

[tsedge]

The output is not related to the input

The EV6 was capped at 3.5 output despite having a higher input than the MG4

Have Trophy so bigger battery with 11kw 3 phase

But the output on the NG4 same as the EV6 is only single phase

That makes sense as 3 phase not really useful.

 

[deanhalllincoln]

Nice info stageshoot ty for sharing.

have you tested your RCD’s in your house when you are on the V2L supply do they still disconnect the supply when you press the test button?

 

[Stageshoot]

Nice info stageshoot ty for sharing.

have you tested your RCD’s in your house when you are on the V2L supply do they still disconnect the supply when you press the test button?

Yes all tested and working

 

[Ayoull]

Hi guys since reading this thread I have been thinking how I can create a similar setup for my house as the original poster using V2L to supply my entire house. Stageshoot appears to have a TT earring system where as I have a TNCS earthing system. My house is approx 25 years old and the consumer unit is a split type with main switch controling all circuits and a 30ma RCD protecting about half the circuits (sockets etc…).

installing a 100A change over switch in the tails from the meter to the consumer unit and an additional time delayed 100A RCD 100mA to protect the entire instalation is no problem. The earth wire from the car would be connected to the earth terminal in the changeover switch and hence to the main earthing terminal of the house at the cutout.

However, as I am on TNCS do I leave my main earthing conductor from the Consumer unit connected to the Neutral at the cutout? One one hand the TNCS combined neutral and Earth is a far better return path to earth where current would only flow in the event of a fault in my house. The fault current would be restricted to a maximum of 100mA and then the main RCD would trip. I suppose I could make the main RCD 30mA non time delayed and restrict fault currents even further.

Or

Do I convert the earthing system to a TT system and disconnect the house from the TNCS system at the cutout? This has the advantage that no fault currents would flow along the DNO’s neutral wire but the path to earth would be far higher resistance. Although it does provide protection against any PEN faults even though these are very rare.

Or

Do I leave the TNCS earthing connected and install an additional earthing rod to the main earthing terminal as an additional path to earth? there Is no reason why I cannot do this as many houses converted to TNCS leave the old main earth rods connected. Any fault current would naturally flow along the low resistance PEN conductor but in the event of a PEN fault there is an alternative path back to earth via the earth rod.

I did consider switching the main earth conductor in the changeover switch (would have to be 3 pole) so the installation switches between TNCS (when on main supply) to TT (when on car supply) but the cross sectional area of the main earthing conductor would not be maintained through the changeover switch.

I’m struggling to figure out the correct way to go here. I want to have the right fault protection in my house when connected to mains and don’t want to push current down the DNO’s cables if they has engineers working on them and think they are isolated.

Have I missed something anything that I would be considering?

any thoughts would be gratefully received.

Dean

You will have to change over your earth as you cannot utilise the DNO earth while in "island" mode as you could potentially kill a jointer or engineer on the network as any faults on your now independent system will still flow back into the DNOs network.

Also as above you will need a proper assessed network level earth grid as even a TT utilises the DNO earth's through other electrodes in the ground, earthing is a massive part of network design and is even more important when trying to operate off grid

Nice info stageshoot ty for sharing.

have you tested your RCD’s in your house when you are on the V2L supply do they still disconnect the supply when you press the test button?

The test button does nothing except make sure the mechanism operates mechanically.

You'd need a proper rcd tester to inject test current to see if it actually operates electrically

 

[FiferMG4]

Wasn’t sure where to put this video, but thought this the most appropriate thread:

 

[Stageshoot]

Wasn’t sure where to put this video, but thought this the most appropriate thread:

With a V2L Lead with a 2K Ohm Resistor fitted you will get a max of 2.5Kw at 220v before the car trips

With a V2L Lead with a 470 Ohm Resistor fitted, you will get a max of 7Kw at 220v before the car trips

I have pushed ours to a constant of 30 amps for an hour and its been fine, but you need to make sure your entire run it a 7kw capable cable and connectors

 

[Purclewan]

You will have to change over your earth as you cannot utilise the DNO earth while in "island" mode as you could potentially kill a jointer or engineer on the network as any faults on your now independent system will still flow back into the DNOs network.

Also as above you will need a proper assessed network level earth grid as even a TT utilises the DNO earth's through other electrodes in the ground, earthing is a massive part of network design and is even more important when trying to operate off grid

The test button does nothing except make sure the mechanism operates mechanically.

You'd need a proper rcd tester to inject test current to see if it actually operates electrically

Ayoult,

Sorry to be thick but if an installation is working in complete island mode (inc disconnecting Neutral/Earth) what has the DNO got to do with anything in a private installation and how is an island setup affecting or affected by the DNO earthing. Surely the two things are totally separate.
If someone decides to set up a private system outside the DNO network what is there to stop them? I agree any work should be carried out to relevant standards but surely that is up to the individual not the DNO or have I missed something.

Also as above you will need a proper assessed network level earth grid as even a TT utilises the DNO earth's through other electrodes in the ground, earthing is a massive part of network design and is even more important when trying to operate off grid

 

[Ayoull]

Ayoult,

Sorry to be thick but if an installation is working in complete island mode (inc disconnecting Neutral/Earth) what has the DNO got to do with anything in a private installation and how is an island setup affecting or affected by the DNO earthing. Surely the two things are totally separate.
If someone decides to set up a private system outside the DNO network what is there to stop them? I agree any work should be carried out to relevant standards but surely that is up to the individual not the DNO or have I missed something.

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.

 

[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.

Understand the logic but who says that the DNO has the ultimate authority?

 

[Cocijo]

How about completely bypassing the meter and getting foc grid electrons?

 

[Ayoull]

Understand the logic but who says that the DNO has the ultimate authority?

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.