EV home chargers?

deandean

Just something out of interest - has anyone seen how the home chargers for electric cars are installed?

e.g. the charger for the 2013 Nissan Leaf is 6kW, and if the car was charging while you were having a T90 shower etc etc, you'd be overloading the fuseboard.

[edit] 1,000th post. Wu-hoo

tomdempsey200

you'd have to determine if the supply is adequate for the additional load........



what kilowatts per charge roughly and charge duration are we talking on average

if it was going to be run on nightsaver there'd be no additional load in that case anyhow...but that wouldn't always be possible i imagine

2011

As tomdempsey200 has said you need to know what size the loads are and what the maximum import capacity (MIC) for the installation is (12kVA is the typical supply requirement for a domestic installation and 16kVA is the typical supply requirement for a larger domestic installation).

I would not imagine it would be an issue, but it is worth checking.

If there was an issue it would not be difficult to install an interlock (using a contactor) so that the EV charger would disconnect while the shower is in use and then reconnect when the shower is off. There are a number of ways that this could be achieved including using current sensing relays.

iopener

as 2011 has you already said can a shower interlocking contactor, ABB make these, all it is a 40 amp contactor with one set of normally closed contacts and a one set of normally open contacts,you could use the normally closed conatcts for the charger and the normally open for the shower,you switch the contactor on/off via a pullcord switch in the bathroom just like a shower,therefore only heavy load is on at any given time.

tomdempsey200

iopener wrote: »

as 2011 has you already said can a shower interlocking contactor, ABB make these, all it is a 40 amp contactor with one set of normally closed contacts and a one set of normally open contacts,you could use the normally closed conatcts for the charger and the normally open for the shower,you switch the contactor on/off via a pullcord switch in the bathroom just like a shower,therefore only heavy load is on at any given time.

prob not that way here..

maybe run the charger through the sensing relay and lock out the shower via 2-pole NC when the chargers drawing over 10amps or whatever the threshold is

iopener

yup you could do it that way alright,depends who will be doing the job, i'm not sure the average joe blogs sparks would go down the route of current sensing relays,this could all be a hypothetical,but there's many ways to skin a cat.

tomdempsey200

yes

i'm thinking the car charger would want priority if using interlock

i'm guessing it may also be bad to interrupt charging..

Bruthal

tomdempsey200 wrote: »

yes

i'm thinking the car charger would want priority if using interlock

i'm guessing it may also be bad to interrupt charging..

Which would be worse, interrupting the battery charging, or the woman in the shower....

iopener

The original post says the charger is 6kva, I would most likely be 6kva at 12 volts or 24 volts meaning the 230 volt supply could be taken off a 16 amp plug, we have 40 amp multi stage chargers in work off 16 amp sockets.

2011

iopener wrote: »

The original post says the charger is 6kva, I would most likely be 6kva at 12 volts or 24 volts meaning the 230 volt supply could be taken off a 16 amp plug

If the output is 6kVA then the input can only be larger than 6kVA (due to losses).

An input of 6kVA would require an input of about 26A at 230VAC, so a 16A socket outlet would not be sufficient.

deandean

Yea the 2013 chargers are 6kVA input which is region 25A. Previous home chargers were approx 3.5kVA, about 16A which you'd be able to add to your consumer board without worry.

It's new ground; Nissan says 'Free Installation' but I have yet to hear of how this is done, hence my post. If my ESB MIC has to be increased there'd probably be an increase in standing charges.

My main worry is, I have seen a few cases where the main switch/fuse gets cooked because of a small-enough overload over time, i.e. you're drawing 70A or 80A periodically, not enough to blow the main fuse but enough to heat it up.

On another note, apparently the next generation of electric vehicle chargers are going to be very intelligent, to the point where the EV battery becomes part of the National Grid. This will become useful when the country has like, 50,000 or more EV's and the batteries become a sizeable storage capacity (the Green Party reckons this will happen in 2016 :pac:). So all these cars will be connected to the National Grid through very smart chargers, and if there is a sudden increase in grid demand, power flow can be reversed so that the battery in your car is feeding the grid and of course the user is paid per kWh in reverse!

Bruthal

iopener wrote: »

The original post says the charger is 6kva, I would most likely be 6kva at 12 volts or 24 volts meaning the 230 volt supply could be taken off a 16 amp plug, we have 40 amp multi stage chargers in work off 16 amp sockets.

It won't just be 6kw on the low voltage side. Its 6kw output probably, so will be higher input.

Them 40 amp chargers are likely nearer 1kva than 6.