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Home charging options
- Thread starter Dangerous Fish
- Start date
WannabeOwner
Well-Known Member
7kW is similar to cooker wiring ... maybe you will charge your car overnight to get best off peak tariff ... in which case Cooker, Power-Shower, Car won't all be on at the same time ... but ... the higher your house limit / fuse / "tails" are the more you can do simultaneously and not have to worry about it.
Car has ability to do geofenced schedule charging - e.g. you can set charging to start at say 1AM when at "home" and it will charge straightaway when at "work", so you would have to explicitly override scheduled-charging at home if you needed to go out again "soon". Thus unlikely you will have car charging same time as "cooker"
Worst case you can get a device that will stop the car charging whenever other household loads exceed threshold.
The UMC cable that comes with the car will plug into a 13 AMP socket - about 6 MPH, so should get you 70-ish miles overnight.
Only real issue is that the wiring for the socket you plug into might not be great for continuous operation at 13 AMPs (realistically 10 AMPs). Whenever plugging into an unknown socket I always check if the plug gets warm after 30 minutes or so, and before going to bed. You can reduce the car charge rate (from dashboard) if that is the case - will take longer to charge of course - or try a different socket - e.g. nearer the consumer unit, rather than the tatty one hanging off the wall in the shed, with the frayed lawn mower extension attached!
If you need an extension lead (e.g. when visiting Rellies) I recommend getting a "proper one" of sufficient cable diameter (to prevent voltage-drop and overheating), and with tough outer protection. See @arg's comment upthread Home charging options
I'm a detail-person. You hadn't noticed?
Anything over 32A (P=V*A) =~7kW requires 3 Phase AFAIK.
I based the sheet on a typical home tethered setup. Some EVSEs do have 3-phase built in, some have that as an option. You can filter the sheet on 3-Phase if you want.
MrBadger
Badger out
Thanks for your connector info Baldrick - useful first glance. A number on there that I had not heard about.
I was involved in an EV trial a number of years back, but backed out because of restrictions being put on me by both the trial organisers and the fitters. It's one of those subjects that the more you know about it, the more you realise that you do not know.
Unfortunately/fortunately? I knew some of the people involved in the running of the trial. At that point in time, and I think remains true now, I realised that that as dumb a wall connector could be, the better. I'm pretty sure that these so called smart ones (along with smart meters and electricity tarrifs) are going to have the potential to come back and bite in the future - all to do with demand side response, the unpublished/sinister side to smart metering when you will potentially lose some control over your electricity needs, both physically and psychologically. Carrot and stick, but all that is being talked about right now is the carrot - ask yourself, why is that. Not necessarily a problem as long as one understands what is lurking in the background.
I was involved in an EV trial a number of years back, but backed out because of restrictions being put on me by both the trial organisers and the fitters. It's one of those subjects that the more you know about it, the more you realise that you do not know.
Unfortunately/fortunately? I knew some of the people involved in the running of the trial. At that point in time, and I think remains true now, I realised that that as dumb a wall connector could be, the better. I'm pretty sure that these so called smart ones (along with smart meters and electricity tarrifs) are going to have the potential to come back and bite in the future - all to do with demand side response, the unpublished/sinister side to smart metering when you will potentially lose some control over your electricity needs, both physically and psychologically. Carrot and stick, but all that is being talked about right now is the carrot - ask yourself, why is that. Not necessarily a problem as long as one understands what is lurking in the background.
interbear
Active Member
I chatted with Andersen yesterday, impressed with their responsiveness and communication. Reassured me a bit given my electrics set up and ability of their unit to manage car charging based on other household power consumption as you note. Given the lack of heavy power consumption devices in our household (no power shower for example) I may not need to go the whole hog of 100 amp fuse and upgrading tails to 25mm. I should be fine with getting the fuse upgraded to 80 amps which means no need to upgrade meter tails and tails into the consumer unit. Easier all round. Andersen also said that as part of the installation they test the household for power load and then set the charger up appropriately in terms of power draw to avoid any issues. Makes sense to me.
That’s good advice. I’ll invest in a new extension cable then, the one I have must be 20 years old anyway
I think that's not quite true. Certainly a tumble dryer is the closest most households will get to a large continuous load on a 13A plug apart from heaters (and heaters are usually cycling on a thermost and/or used only when it's cold and so more margin before overheating).
I went looking for data on typical tumble dryers; fortunately the EU labelling directive requires manufacturers to supply data in the form of total consumption per cycle and cycle duration, so you can easily calculate the average power (with two figures for each appliance, full load and partial load). I sampled a range of about half a dozen models from different manufacturers, performance rating "B" and "C", and the highest figure I got was 2.08kW, most were a little less, lowest in my survey was 1.65kW.
This compares to 2.3kW for EV charging with a typical 'granny cable' or the UMC with 13A plug adapter, so it's a little more, and the duration is also typically longer (maybe 90 mins for a typical dryer cycle, then at least a short interval for it to cool down before you start the next load).
A short duration overload doesn't actually cause any problem to wiring, as it takes time to heat up. There's no exact figure for how long is too long, or how long it takes to reach full temperature (it's asymptotic, so the literal answer is infinite), but 2 hours is a good rule of thumb.
So a tumble dryer is pushing quite close to the limit on both current and duration, but the EV charging pushes it further.
Conversely, if you have a 3kW kettle, that's a bigger current (that many "13A" plugs/sockets couldn't sustain long-term), but fortunately it only takes a couple of minutes to boil so it's not a problem in practice.
Actually, with the small amount of load that you listed (no electric showers or other heating), you'd almost certainly never blow even the 60A fuse with a single chargepoint and the rest of your existing loads. People are often spooked by induction hobs with their "30A" rating, but in fact they don't use any more energy than a conventional hob - actually slightly less as they are more efficient - they just use it over a shorter period. So if you are doing the same amount of cooking then you don't use any more energy and for a domestic kitchen it's reasonable to use the same numbers in a demand calculation as for a standard hob (the argument could be different in a restaurant kitchen where the induction hob may let them get more cooking done on the same number of rings).
Upgrade to the 80A fuse should be plenty.
WannabeOwner
Well-Known Member
vitesse
Active Member
I was told it's free by UK Power Networks in our area. But they do ask for preparation in advance!:
I received these texts:
This is UK Power Networks. Customer must arrange for their electrician to upgrade the meter tails to 25mm from the meter to their consumer unit if the upgrade is to 100amps, if you need anything else, do not hesitate to contact us on 0800 31 63 105
and
This is UK Power Networks. Customer must arrange for their supplier to remove exisiting outgoing tails from the meter to upgrade the meter tails to 25mm if the upgrade is to 100amps, if you need anything else, do not hesitate to contact us on 0800 31 63 105
interbear
Active Member
Thanks @arg
Funnily enough Western Power just rolled up unannounced (I called them last week to arrange an appointment), took a look inside my meter cabinet and confirmed that my current fuse is 60 amps. The box/barrel holding the fuse apparently isn’t big enough for a 100 amp fuse so they’d have to change the entire unit and that would be a chargeable upgrade. So, for now, they swapped the 60 amp fuse out for an 80 amp fuse. So that part of the upgrade is done and based on advice from both Andersen and the friendly chap from Western Power, as well as yourself, I’m pretty confident it will sufficient for my planned 7kwh home charger.
As I was expecting to need a 100 amp fuse I also have EDF arriving next week to upgrade the meter tails from 16mm to 25mm. Not really necessary for the 80 amp fuse but it’s free so I may as well still get that done so it’s future proofed if I want to upgrade to 100 amp fuse further down the line. Some good news also is that the Western Power chap was of the opinion that the tails from the meter into the consumer unit were already 25mm.
Progress. Although being a non sparky I still don’t understand why cables are called tails
vitesse
Active Member
Getting meters changed for Octopus Go next week and will ask them to ensure the 'tails' (I share your wonder!) are 25mm.
Anyone know what charge adaptors (if any) come with the M3?
I'm hoping to use the 7kw PodPoint we have at home but its a tethered Type 1 so will need an adaptor to convert to Type 2.
EDIT: Does anyone know if the onboard chargers on SR+ and LR/P models are different? I've see both 7Kw and 11Kw mentioned but I'm not sure which is accurate, maybe 7 for SR+ and 11 for LR/P, or both 11 ?
I'm hoping to use the 7kw PodPoint we have at home but its a tethered Type 1 so will need an adaptor to convert to Type 2.
EDIT: Does anyone know if the onboard chargers on SR+ and LR/P models are different? I've see both 7Kw and 11Kw mentioned but I'm not sure which is accurate, maybe 7 for SR+ and 11 for LR/P, or both 11 ?
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Unless you are still using the Type 1 it might be better to get your PodPoint converted directly to a Type 2 rather than use an adaptor.
Useful Info from the Tesla website:
Home Charging Installation
Charging Connectors
Max is 11kW for all Model 3s, but 7kW is plenty.
Yes, you'll need a Type 1 to Type 2 adapter, google it.
GraemeS
Member
vitesse
Active Member
Had my EO charger installed yesterday. Turns out I have a 30A fuse on a cable head that looks like it's been around since the turn of the century (previous one) when the house was built
No showers or cooking while charging until I get that replaced!
Our ROLEC charges at 32A - presumably you need to limit your current with only a 30A fuse?
