MG4 powering other stuff (Vehicle to Load aka ‘V2L’)

[Martinonline]

See also the thread titled 'MG4 Discharge Cable'.

 

[wattmatters]

The MG4 Inverter is capable of delivering 32 Amps at 220 volts which equates to 7kW of power. Most of the V2L adapter cables limit the output to 2.2 kW or thereabouts for good reason.

Yep. Here the 2.2 kW limit for "official" V2L adapters makes sense given our standard plugs/sockets/cables are only 10 A rated.

In the UK they more commonly supply 16 A / 3.5 kW V2L adapters given standard plugs/sockets/cables over there are 13A rated, and are usually connected to a 30 A ring circuit. People would be used to being able to plug in a standard 3 kW kettle for example.

 

[siteguru]

In the UK the 13A outlets are only related to 10A continuous. (BS1363-1 refers).

 

[wattmatters]

10A continuous

How long is considered "continuous"?
e.g. 3 kW kettles are common and if full would take minutes to boil.

 

[siteguru]

Dunno - I just know that the granny chargers here with 3-pin plugs are limited to 10A due to the BS1363 standard.

 

[GabiV]

See also the thread titled 'MG4 Discharge Cable'.

That is an awesome thread, thank you so much.

 

[Coulomb]

3 kW kettles are common and if full would take minutes to boil.

But electrical wiring takes more than a few minutes to get dangerously hot.

 

[Corindikev]

I believe if the 20 mtr extension cord was 4mm2 cable, it could carry the 32 amps if the cable was in open air.
An electrical device called an RVD Residual Voltage Technology - Residual Voltage Technology will protect against an electric shock where a 2 wire floating supply is used. It is referred to as a "floating system" because neither line 1 of line 2 and connected to the earth circuit, the RVD looks for voltage on the earthing circuit rather than current imbalance between the active and neutral. Double pole switching is still required because both line 1 and line 2 are active .....

T1 Terry

You are correct but there will be greater than the allowable 3% voltage drop or 7.18 volts. 4mm² cable is rated for 31 amps but carries 32 fine for 10 metres or less. If you are drawing 32 amps over 20 metres you will definitely need to have the cable well ventilated as it will get quite hot which equals energy loss.

I bought a V2L adaptor from China (AliExpress I think) & it is rated at 32 amps. Cost me $40.00 & is solidly made. It was only available for a short time & the output was then reduced to 16 amps. It works perfectly & I keep it in the same bag (school kids backpack) as the granny charger under the bonnet.

The limit of course is the extension lead. I've run the fridge , freezer, lights & TV and used the electric jug (2.2kW) & toaster (1kW), electric frypan (1.8kW) as well but not all at the same time during power cuts. This is all I need so have not bothered to buy a heavy duty cable.

 

[T1 Terry]

You are correct but there will be greater than the allowable 3% voltage drop or 7.18 volts. 4mm cable is rated for 31 amps but carries 32 fine for 10 metres or less. If you are drawing 32 amps over 20 metres you will definitely need to have the cable well ventilated as it will get quite hot which equals energy loss.

Just because it can supply 32 amps, it doesn't mean you should be using all of the 32 amps continuously. Having the cable that can carry the load required for short term high current loads like multiple induction motors all trying to start at the same time ..... a rare occurrence, but it does happen .....

I thought the low voltage sparkies had a 5% voltage drop max. figure they worked on, I remember the level of frustration I had with a number of customers who quoted the 5% rule to me and in the end I just mentioned I was dealing with 12V DC not 240V AC, 5% loss at 12V = 11.4V at the other end of the cable, where a 5% loss at 240V = 228V at the other end of the cable ...... sometimes they got it, sometimes the figure was so burnt into their brains that just couldn't accept it didn't apply to all circuits.

T1 Terry

 

[Coulomb]

in the end I just mentioned I was dealing with 12V DC not 240V AC, 5% loss at 12V = 11.4V at the other end of the cable, where a 5% loss at 240V = 228V at the other end of the cable ...... sometimes they got it, sometimes the figure was so burnt into their brains that just couldn't accept it didn't apply to all circuits.

I must be one of those people with limited vision. To me, 5% voltage loss is the same for both AC and DC, low voltage or extra low voltage or high voltage.

I also prefer to limit drops to 2%.

 

[Corindikev]

I should have said 3% is desirable, not allowable so 5% is OK. Now electrical authorities are recommending 3% max. Like everything things keep getting tightened.

The standard AC voltage to homes in Australia is 230 volts but the allowable range is from 216.2 to 256 volts or minus 6% to plus 11%. Where I live in NSW it usually varies from 230 to 240 volts.
My EVSE automatically adjusts the Amps it draws to suit the voltage and supply so the car gets the most it can charge the battery at which is 6.6kW.

 

[T1 Terry]

I should have said 3% is desirable, not allowable so 5% is OK. Now electrical authorities are recommending 3% max. Like everything things keep getting tightened.

The standard AC voltage to homes in Australia is 230 volts but the allowable range is from 216.2 to 256 volts or minus 6% to plus 11%. Where I live in NSW it usually varies from 230 to 240 volts.
My EVSE automatically adjusts the Amps it draws to suit the voltage and supply so the car gets the most it can charge the battery at which is 6.6kW.

The power at the house in Lake Illawarra was anywhere from 195vac to 265vac, the old filament bulbs would last 6 weeks at the best and we lost a few fridge/freezer motors. Eventually replaced all the lights with fluro bulbs and put the fridge/freezers on off grid, that seemed to solve the problem.

When we first moved into the house in Mannum, we were on the end of a SWER line and that fluctuated from so little voltage we could only have a single 40w filament bulb switch on and even that was a very brown flickering affair ..... till the sun hit all the solar panels down the line, then we had 265vac and popped bulbs at an alarming rate. Gradually replaced them all with LED bulbs, but I always worried about the fridge/freezer motor .... place burnt to the ground since, so no need to worry about unstable mains voltage any more

T1 Terry

 

[wattmatters]

But electrical wiring takes more than a few minutes to get dangerously hot.

Hence my question:

How long is considered "continuous"?

 

[Everest]

See also the thread titled 'MG4 Discharge Cable'.

- yes, see my link in post #4 to that thread.

standard plugs/sockets/cables over there are 13A rated

In the UK the 13A outlets are only related to 10A continuous. (BS1363-1 refers).

10A continuous is correct, though there is a recommendation to limit continuous use for max of 8A only (2000W @ 250V) and for the socket to be supplied on a dedicated circuit (i.e. not on a ring final).

How long is considered "continuous"?
e.g. 3 kW kettles are common and if full would take minutes to boil.

Dunno

Off the top of my head I think it is for the plug and socket to not rise above 55 degrees C after 4h continuous use and then to be thermally stable for another 4 hours - so 8h test in total to pass compliance.

Having said that, my experience is that it is either a cheap, poorly made plug or the old socket in the house that has become warn with tarnished contacts that will result in increased resistance and hence too much heat that can't be dissipated.

A 3kW kettle is only on for a few minutes, so not issue. Similarly, the old 3kW convector heaters (which are almost impossible to find these days) are usually on and off via a thermostat. Similarly for a washing machine that is only heating at about 2.5kW for 20 to 30 mins max.

But electrical wiring takes more than a few minutes to get dangerously hot.

Just because it can supply 32 amps, it doesn't mean you should be using all of the 32 amps continuously. Having the cable that can carry the load required for short term high current loads like multiple induction motors all trying to start at the same time ..... a rare occurrence, but it does happen .....

and not rare for a power-outage V2L situation. For example, our previous 3.6kW inverter would fail to start up our house load which included 2 fridges and 2 freezers in one go. I had to turn the fridge/freezers off, then put them on, one at a time. Start up current can be 10x or more the value of the running current for an inductive load.

 

[Everest]

Hence my question:

see my reply above An EV charger is likely to be on for more than 4h.

 

[wattmatters]

The power at the house in Lake Illawarra was anywhere from 195vac to 265vac

Our voltage over the last few days:

 

[wattmatters]

see my reply above An EV charger is likely to be on for more than 4h.

We are talking about V2L though, not EVSE.

 

[Everest]

We are talking about V2L though, not EVSE.

Yes, but the discussion drifted to ratings of our 13A sockets on 30A ring finals, which I was trying to clarify after @siteguru's correct comment about 10A.

The MG4 V2L only supports 2.2kW at something like 218V AFAIR.

 

[T1 Terry]

- yes, see my link in post #4 to that thread.


10A continuous is correct, though there is a recommendation to limit continuous use for max of 8A only (2000W @ 250V) and for the socket to be supplied on a dedicated circuit (i.e. not on a ring final).


Off the top of my head I think it is for the plug and socket to not rise above 55 degrees C after 4h continuous use and then to be thermally stable for another 4 hours - so 8h test in total to pass compliance.

Having said that, my experience is that it is either a cheap, poorly made plug or the old socket in the house that has become warn with tarnished contacts that will result in increased resistance and hence too much heat that can't be dissipated.

A 3kW kettle is only on for a few minutes, so not issue. Similarly, the old 3kW convector heaters (which are almost impossible to find these days) are usually on and off via a thermostat. Similarly for a washing machine that is only heating at about 2.5kW for 20 to 30 mins max.





and not rare for a power-outage V2L situation. For example, our previous 3.6kW inverter would fail to start up our house load which included 2 fridges and 2 freezers in one go. I had to turn the fridge/freezers off, then put them on, one at a time. Start up current can be 10x or more the value of the running current for an inductive load.

What brand inverter? The 5kVA Victron can supply a 200% load for up to 5 mins if the temp is low enough, and a 1 sec overload rating of 53 amps. Never had one shut down because of an overload, but they do carry on a right treat until the load drops

I wonder how one of those would go with the V2L supplying the grid feed and limited to say 20 amps, that way the inverter would kick in to take up any overload, then revert to a battery charger as soon as the load dropped below the 20 amp input with what ever was available ....

T1 Terry

 

[Everest]

What brand inverter? The 5kva Victron can supply a 200% load for up to 5 mins if the temp is low enough

It was a 3.6kW HF Solis hybrid inverter. They're not capable of the same inrush-current that a heavy duty LF inverter, such as the Victron can supply

I wonder how one of those would go with the V2L supplying the grid feed and limited to say 20 amps, that way the inverter would kick in to take up any overload, then revert to a battery charger as soon as the load dropped below the 20 amp input with what ever was available ....

My inverter doesn't have a generator input, as some do. I will connect the V2L via a chargeverter or similar direct onto the 48V battery supply - when I get an MG4, that is!