Guy rang me yesterday, He wants to plug his EV in and charge it overnight at his static caravan. He only has a 2OA supply: that's fine he can in theory plug in via a 13A socket and trickle charge. What he wants/needs is some sort of management system that will turn off his charger if he turns on say kettle and toaster first thing; I don't even know if this sort of thing is available, I would think it would have to be installed at the CU and won't be cheap. I think I'm going to tell him he needs to speak to a registered EV point installer, as (before I even look) there's probably all sorts of issues here with liability, and additional earthing requirement/ RCD issues, but any thoughts? It''s an interesting and not unreasonable question, and i guess likely to be commonplace in the future. You have a static: how do you charge your car when you're there?
Load shedding switches are a fairly common item on the continent, especially in the warmer south where electric heating is rare, and supplies are thinner.
(An example from eaton) This 15/32A unit closes its relay contact (rated at 1A only) when the load through its sense coils exceeds 15A, though it will take loads up to 32A without damage. Other sensitivities are available and may be better suited.
IF the charger will stand being cut off and then reconnected, sensing the socket circuit loads and using the current sensor relay contact to drop a contractor in series with the supply to the charger socket might be an easy way to tackle the maximum load issue.
Sort of thing will require a small DIN box enclosure for the sensor and the contactor - how easy that is will depend on the space available and the layout of the wiring. And do not sense the load that will be dropped, or it will oscillate ?.
If the charger needs something less brutal than a power cut such as an ethernet or RS232 command to be sent, then a current transformer and an Arduino may be the way forward for those who can program in C, an option not for the faint of heart however.
Load shedding switches are a fairly common item on the continent, especially in the warmer south where electric heating is rare, and supplies are thinner.
(An example from eaton) This 15/32A unit closes its relay contact (rated at 1A only) when the load through its sense coils exceeds 15A, though it will take loads up to 32A without damage. Other sensitivities are available and may be better suited.
IF the charger will stand being cut off and then reconnected, sensing the socket circuit loads and using the current sensor relay contact to drop a contractor in series with the supply to the charger socket might be an easy way to tackle the maximum load issue.
Sort of thing will require a small DIN box enclosure for the sensor and the contactor - how easy that is will depend on the space available and the layout of the wiring. And do not sense the load that will be dropped, or it will oscillate ?.
If the charger needs something less brutal than a power cut such as an ethernet or RS232 command to be sent, then a current transformer and an Arduino may be the way forward for those who can program in C, an option not for the faint of heart however.
