Electric vehicle charging point

[bernardgreen]

They are actually a 7 pin connector known as a typ2-stecker

The seven pin is a proposed standard. As the manufacturers page states

The world's three standardized systems for charging connectors for electric vehicles are incompatible with each other. Since type 1 only allows single-phase load, it plays no role in the three-phase European networks. Three-phase networks are only supported by type 2 and type 3. Across Europe, there were proponents of both systems.
From the consumer perspective, however, a single system is desirable, at least for Europe, because only uniform connection technology enables anywhere easily charge the battery and so to ensure our mobility internationally.

Translation by Google to save me work

 

[bernardgreen]

While the ideal would be for the 230 volt circuits ( 440 in a three phase charger ) to be isolated from the vehicle chassis and body and that ideal may be fact in a car new out of the factory normal wear and tear has to be taken into account along with ignorant drivers ( charging the car after it has been driven through flood waters ) and the isolation may be compromised.

Hence the charging system should allow for the 230 ( 440 ) volt circuits to have some leakage to the chassis / body so the chassis must be connected to an "earth" in the charging point socket. Then we come into the realm of exporting a PME "earth" to electrical tools in the garden. The car is just a big metal tool and thus should not be "earthed" by connecting it to an exported PME "earth".

Therefore logically the charging point "earth" should be a local TT type, preferable from an earth mat under the are where the vehicle being charged is parked.

Having seen the standard of design and maintainance of electrics in some lamp posts and similar street furniture I would be wary of any public charging point.

 

[ericmark]

I'm surprised the guidance is not out there in the regs now EV's are on sale.

Sometimes, even the experts don't know what to do for the best!

There is Code of Practice for Electric Vehicle Charging Equipment Installation it would cost me £35.75

Wiring Matters Issue 48 - Autumn 2013 also has some details plus Issue 45 - Winter 2012 and Issue 44 - Autumn 2012.

In the main it's the PME risks which seem to be main question. With a house on a TN-S or TT it's straight forward.

I have argued the same with caravans stored at home and with the battery being topped up with house supply. Where my father-in-laws motor caravan and our caravan is stored it's often less than a meter from the electric and gas cupboards to have a different earth to the vehicles then the house is clearly not the thing to do.

However my second caravan stored and used by my son is a good 20 foot from the house so in that case using TT for caravan is not a problem. On a caravan site the fire regulations mean no caravan is placed close to a building but this is not the case with home storage.

In the same way a car being charged in a garage will clearly use same earth system as garage but as we move away from building there has to be a risk assessment as to the chances of touching two different earthing arrangements and it needs the skill of the electrician to assess that risk there is really no cut and dried answer.

 

[westie101]

From

Charging of Electric Vehicles at Domestic
Dwellings Using Protective Multiple Earthing
(PME) – Risk Analysis
PE01417/2012/1

EXECUTIVE SUMMARY
The use of electric vehicles is set to grow as economic and environmental concerns create a need to reduce reliance upon fossil fuel technologies. As with any new technology, there are risks and benefits associated with the deployment of electric vehicles.

The Institution of Engineering & Technology (IET) have produced a code of practice, through IET Standards Ltd, which aims to ensure the safe design, installation and maintenance of fixed electrical equipment used for charging vehicles.

During the consultation process on the draft code of practice, concerns were raised about the connection of charging equipment to supplies in domestic dwellings using Protective Multiple Earthing (PME) and the possibility of electric shock under specific fault conditions on the electricity distribution network. As a result of this the published code of practice effectively prohibited the connection to PME supplies for outdoor vehicle charging.

Whilst this avoids the risks associated with PME, it had the potential to give rise to other risks associated with the alternatives as well as being costly and inconvenient for consumers.


Objectives
To objectively determine the level of risk associated with using PME supplies at domestic dwellings in comparison with the risks associated with the alternatives (if data to do this exists), in order to assist evidence-based decision making as to whether to revise the code of practice to allow the use of PME in outdoor electric vehicle charging.
This was achieved by undertaking a formal risk review using event tree analysis together with a sensitivity assessment.


Main Findings
The increase in individual risk of a person being seriously injured or killed associated with permitting the use of PME supplies for charging electric vehicles outside of domestic dwellings was assessed to be within the range 1.1 x 10-6 to 7.8 x 10-9 per year, depending on the assumptions made.
This increase in risk will not apply to those individuals who will not come into contact with an electric vehicle, and the number of these individuals will itself depend on the number of electric vehicles in use in society.
The upper increase of risk of 1.1 x 10-6 (just over one in a million) chance per year of injury or fatality is the order of magnitude of the ‘Tolerable’ region in risk tolerability criteria published by the Health and Safety Executive. However, given the large amount of uncertainty in the values used to calculate these risks then a large amount of conservatism has been built into these figures.

It is therefore considered that the increase in risk seen from the use of PME supplies for charging electric vehicles at domestic dwellings is unlikely to increase the risk from the ‘Broadly Acceptable’ region, assuming that the base level of risk from electrical hazards to a normal household is already within this region. With this level of risk additional control measures to reduce risk should be implemented if it is reasonably practicable to do so, but a less onerous justification would be required than if the risks were to fall in the higher risk ‘Tolerable’ region.

This finding is also based upon a number of fixed assumptions about the nature of faults on electricity distribution networks, in particular the reliability of their detection and the speed of rectification.
vii


Recommendations
IET Standards should share the findings of this work with those responsible for any proposed amendments to the Electric Vehicle charging code of practice and JPEL64 –Joint IET/BSI Technical Committee for Electrical Installations. The modelling assumptions made should be reviewed by key stakeholders to ensure that they reflect the operating experience of other stakeholders, in particular Distribution Network
Operators (DNO) other than those providing data to the project team.
No judgements should be made about the deployment of PME supplies to other applications more broadly than the outdoor domestic electric vehicle charging based on this work. This is because the datasets used and the assumptions made model only the narrow circumstances in which electric vehicles would be charged at a domestic dwelling

Reading all of that it also refers to a Code of Practice dealing with vehicle charging that i think installers MUST have a copy of before doing any work. It also, to me, implies that BS7671 may not be amended to contain these details

 

[winston1]

While the ideal would be for the 230 volt circuits ( 440 in a three phase charger )

Erm!

230v single phase works out at 400v 3 phase
440v 3 phase is 254v on a single phase.

For reference it is:

127/220
220/380
230/400
240/415
254/440

 

[ban-all-sheds]

What size is the supply likely to be?

Depends on the car - he needs to decide what he's going to have. or might have, and find out from the maker(s).

e.g. I believe that a Tesla with the high-power charging option needs a 100A supply (single-phase).

What sort of connector does it use?

Whatever standard connector you'd use to plug in a load that needs x A at yV. So over here that would be an IEC 60309. You should find out if he has/can get/would like 3-phase, if his car can use it.

He might like to have his own EVSE box hard-wired in, which would provide an IEC 62196 outlet.

http://en.wikipedia.org/wiki/Charging_station

http://images.google.com/images?q=evse

Anything else to consider?

How about how on earth we could ever build a network of EV charging stations or facilities which could deliver the same, or even reasonably equivalent, rate of energy transfer, as a petrol or diesel pump. At 40l/min a pump is delivering about 400 kWh/minute. Assuming it takes you 2-3 x as long to go and pay as it does to fill up, a busy petrol station with a dozen pumps would need an electricity supply of the order of 100MW to equate.

OK - that ignores the relative efficiency of IC vs electric motors in cars, and the willingness of drivers to hang about for longer to fast-charge their vehicles, but even if those combine to knock an order of magnitude off, how are you going to deliver 10MW to your typical non-motorway garage?

Where are we going to get all that electricity from? By keeping coal-powered power stations running? Does that make EVs lower polluting than a modern IC engined vehicle, or does it just move the pollution somewhere else?

Like FITs the whole idea collapses if everybody decides to drive electric cars, and like FITs, it looks as if the vehicle excise duty, purchase grants, congestion & parking charges, free charging circuit installation etc incentives are going to be used to make everybody else pay to subsidise the pointless vanity projects of the smugly ignorant.

 

[bernardgreen]

depending on the assumptions made. ~~~~~~

unlikely to increase the risk from the ‘Broadly Acceptable’ region, assuming that the base level of risk from electrical hazards to a normal household is already within this region ~~~~~~~

fixed assumptions about the nature of faults on electricity distribution networks ~~~~~

Quite a few assumptions

And while one fatality per million may be considered as Broadly Acceptable by 999,999 people the friends and family of the dead person may have a different opinion about what is broadly acceptable.

No doubt that after the first serious injury or fatality caused by the use of ""broadly acceptable"" methods of charging an electric vehicle there will be a knee jerk reaction and the validity of the assumptions on which decisions were made will be re-assessed.

 

[ban-all-sheds]

In the UK alone, since the motor car was introduced, several hundred thousand people have lost their lives to it, and tens of millions have been injured.

I see no evidence of any reassessment of whether the car is an acceptable thing to have.

But if you want to predict hand-wringing when someone is electrocuted by an EV charging connection, will you do likewise when a pedestrian is killed or injured by an EV because they didn't hear it?

 

[ericmark]

The surprise is they consider it as something new. We have been charging batteries in caravans, motor caravans and boats for many years and we have away from the house always used either a TT or earth free supply the latter mainly with boats where an isolation transformer is used.

When I came to wire a boat my first thought was to only take shore power to the battery charger which would have an isolation transformer so no need to import the earth.

However when I came to look at the stage charger it was not class II so that was not an option so used diodes in the earth instead.

The major problem is all our isolators with the exception of plugs and sockets don't switch the earth so no RCD would help. Well may be a ELCB-v which puts a resistance in the earth would but these were banned many years ago.

It is really down to the charger design in the car if the charger is Class II then there is no problem only when class I does the problem arise. Caravan chargers are still in the main class I and really it would not be that hard to manufacturer class II chargers if the charger was class II it would not be that hard to have a storage power point and a usage power point so when stored only the battery charger was used.

There is one electric van in our road and the charge point is less than a meter from the van and gas and electric cupboards also the vehicle is less than a meter from the foot path with no gates so any passer by could touch it. It was wired by British Gas not a clue what earth was used but no sign of any earth rod so would assume TN-C-S.

In the old days the charger was not built into the fork lift or milk float and the DC lead was isolated by the transformer from the building earth.

The only really safe way would be an isolation transformer but cost would be huge.

Faults on PME supplies which mean the earth/neutral voltage raises above 50 volt from the surrounding ground voltage are very rare. I personally only found it once. I think the likely hood of any one getting a shock is very remote.

But it all returns to same thing. One has to do a risk assessment for each installation one can't really hide behind convention.

 

[westie101]

And while one fatality per million may be considered as Broadly Acceptable by 999,999 people the friends and family of the dead person may have a different opinion about what is broadly acceptable.

Though a bitter pill to swallow the reality of a zero risk environment only exists in the minds of the media, the "handwringers" and the lawyers (possibly politicians for political reasons as well).
Even the likes of the HSE accepts there is risk up to fatalities but strives to reduce it.

 

[ericmark]

A pedestrian is killed or injured by an EV because they didn't hear it?

This caused the demise of the silent rider bus in Chester back in the 1970's it is nothing new. And yes guilty as charged when riding my bike I don't always use my eyes I often use just my ears to be aware of cars behind me.

 

[bernardgreen]

Though a bitter pill to swallow the reality of a zero risk environment only exists in the minds of the media

I agree and accept that,

I just question if the assumptions are valid.

In many areas I feel the assumptions are selected to achieve a predicted risk that is "broadly acceptable" and assumptions that would predict a higher (un-acceptable ) risk are conveniently dis-missed at the time the regulations are created.

 

[ericmark]

e.g. I believe that a Tesla with the high-power charging option needs a 100A supply (single-phase).

I note the Tesla has many options as to charge rate demanding up to 22 kW. But I think there is a single, split, and three phase option so for domestic normal would be 16A although they recommend the 7.4 kW version.

I am sure guy up the road uses 16A which over the afternoon and evening should fully recharge the van giving a 90 miles range. He is a milkman as as such has a fixed mileage of 68 miles well within the range offered and since in and out all the time he does not use any heaters.

In the summer it works well. However in Winter months he has needed to be recovered when the battery ran flat. He was stopped by Police for going too slow as he tried to cover the last few miles to get home.

It does save him money and he says being silent the street urchin's don't hear him so don't steal milk from him like they did when they could hear him coming. It also means here we are not woken when he leaves the house at 4 am. His round is some 15 miles from his house.

 

[Nozzle]

Off-topic alert:

The future my friends is Hydrogen fuel cell cars. The Hydrogen being produced at the "petrol" station and stored as required. It is produced using an electrolyser from the likes of ITM Power from electric from the grid. Be that renewable, nuclear or gas. As a sneaky side effect, said hydrogen can also be injected (blended) into the national grid to power gas appliances. Hurrah.

The very idea that running a car on electric makes it instantly eco friendly is utter madness - it all depends on how that electric is produced. If it's from some nice Nucs or wind turbines/hydro/tidal then fair enough. If it's produced from Gas or coal then electricity has to be the very very very worst "medium" for using that energy. Much better to fuel the car directly from the gas or gasified coal.

Nozzle

 

[westie101]

I just question if the assumptions are valid.

The actual full report runs to 37 pages and details how the conclusions were reached. However as it is on our secure serrvers I can't link to it.
However it is a public report so may be out there to be read in full.
I would suggest that before deciding on the validity or not the full report needs to be read, along with the CoP referred to.