Have you read the above circuit braker myths? you posted them yourself. They are no catch all solution.
Yes, and I’m a qualified electrical and electronic engineer with a master’s degree. Have you read my answer? As long as one stays withing the ratings you generally would be fine. I already pointed out some risks too. At the end there will always be some point of failure. Houses have been fine dealing with overload situations using breakers for decades (when correctly installed, the right wire gauges are used, etc. etc.).
Sorry, I was not trying to be disrespectful, but reading it back I see I did come across that way. But you also must know circuit breakers are not perfect, and installation errors do occur. For all we know some people with ancient installations are using the above advise to buy and self install a €250, 22kW wallbox bought in a supermarket (I kid you not, I saw one advertised on my vacation).
A question: I own a different brand car, but in my case changing a car parameter may take a while because the car is online only periodically, even when connected to the charger and on home wifi. Did you check how long a Tesla takes to respond to changing the maximum charging rate? Also, my car is cloud connected, and the servers are notorious for outages in busy periods. Maybe Tesla is super reliable, but I would not trust my car integration enough.
All good!
I totaal agree with you. We bought a 40-year old house and I had to struggle for 3 years with the help of a lawyer to get the wiring up to standard, because an invalid compliance certificate was issued, giving me a false sense of safety. Shortcuts get taken all the time. I was lucky to understand and spot some of the issues, plus 200% perseverance to get it fixed (I’m not a qualified electrician though).
I always urge people, especially when they admit that something isn’t their strong suit to get installations done properly. Get it signed off. Buy good equipment.
Yeah, the goal is avoiding the main circuit breaker tripping.
So mains power theoretical max is 14400W so this automation is intended to make sure there is headroom for when dynamic loads like that to kick in.
I might set the max to 9000 and target to 7000 to allow for more headroom.
Good point on additional triggers, I could trigger on the main power exceeding max and another couple of energy monitors in the kitchen and laundry could provide triggers at other values.
Yeah I have reduced the max value and the automation operates correctly.
The 30-second trigger is needed to gradually increase the amps up to above the target value, but the numeric could also be a trigger for max yeah. Doing this I could decrease the timed trigger to 5 minutes or longer as it would only be for increasing the amps.
Thanks for the info on breakers, really interesting. This automation was more of a helper to keep well below the breaker maximums. i.e. max is 60A and this would kick in at say 40A. So yeah I guess instead of avoiding tripping the breakers, this will just reduce stress and wear and them and the wiring.
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Regarding updating the car parameters, from what I can tell while the car is charging that it’s pretty much constantly online so changes are very quick. I assume this because the car systems need to be online to manage the charging process. Other times though I have seen the same, those systems are offline while the car is in deep sleep and you need to wait for it to wake up and poll to push parameters to it.
Be interesting to know if that’s the case with other brand cars.
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I was hoping my Skoda would do the same, there’s not much need to save wifi power when you’re pulling multiple kW from mains, but alas, no. I guess they are protecting server load as well.
For those with a connected wallbox it may be a better alternative to limit charing current that way. Because if you have family over and you let them charge, your automation would not protect you.
Yeah, this automation could work with a charger that is natively supported in HA or supports OCPP integrated with HA or Charge HQ for example. Doesn’t need to be a Tesla.
Personally, I won’t get much benefit from using a smart charger with native load monitoring via a clamp, as the car charges in a separate building from where the main power meter is and we are on single-phase power. I’m waiting for the smart charging tech. to get better - support remote clamps etc.
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The first version of this blueprint is here for anyone interested in trying it out. Have yet to write it up and publish it in the blueprint exchange.
Be good to get some initial feedback from anyone with a Tesla and a power meter at home.
Tesla controlled charge rate based on power sensor (github.com)
This is exactly what I was looking for.
I opted for a Tesla Wall Connector, to charge my Model Y.
I didn’t like the sole option of Shelly EM to turn on/off the charging, I wanted something to adjust dynamically.
My question is, how does the car receive this information? Is it by Internet? It’s parked underground on a -2 floor. Should I get a router to give Wi-Fi to the car?
There is no known way to make the Wall Connector dynamically limit the charge power, right?
Thanks,
Great, be good to get some feedback if you are able to try it out.
The blueprint is now on the blueprint exchange with more details about how it works.
Yes, the car receives the changes via the internet, I know that while the car is charging it’s pretty much constantly online so rate changes are very quick (seconds) when it has Wi-Fi connectivity. In theory, if there is no wifi it would fall back to the Tesla Standard Connectivity (i.e. built-in cellphone network/3G), but I’m not sure if that system sleeps or how much delay that would add.
Haven’t got a Tesla Wall Connector integrated with HA, so I’m not sure if there is any option to change the charge rate. Looking at the integration page it seems maybe not.
Hi, I was thinking of doing the same thing, do you have any updates? How is it going? Can’t you adjust the charge directly from the wall connector?
Thanks!
Here is the blueprint I released. I adjust charge rate from the car, I don’t have a wall connector.
How to force to scan every 1 minutes? My automation works only when i press RUN.
Also are you using the blueprint, this post was just about a test. Use the blueprint and post in that thread if you need help.
BTW, when you click run it skips the trigger conditions for the automation and runs the actions regardless.
The automation is always watching for trigger conditions and onlys runs when those conditions are met.
TBH to be on the safe side I went with this (hardware controlled) - Dynamic Power Management https://www.tesla.com/support/charging/wall-connector/power-management
One downside is Tesla (or the integration) does not expose the attached neurio W2 CT measurement (RS-485) within Home Assistant.
In the past we blew the main 100A fuse (not breaker, needed to call out National Grid to replace in the UK) when the now sold Hot Tub kicked in a nightly cycle and heat + cars/battery charging and baseload…
Yes hardware controlled is better, as suggested in the blueprint post.
When I wrote this the power clamps for those had to be physically connected to the EV charger so I could not use them but now I understand there are wireless ones so maybe an option now for me.
The hardware control of that Tesla option doesn’t actually know the load on the main fuse though does it? Only what other Tesla chargers are drawing.
Yes, it knows the fuse rating and you set it to 80% less, all done within the wall connector, hope this helps