Need help with home charger install

[SparkyR1t]

So a couple of things. Your electrician most likely calculated max nameplate amperage’s from all appliances and is assuming they will all be running continuously. If that equaled to 161 amps then he may have multiples by 25% assuming continuous duty which would require a service to the house of 201 amps

but what you really need is that total appliance amperage value but take into consideration the actual running time of all appliances whether 80% run time or sometime appliances only run 20% during the day or less

this is how a utility typically calculates a service rating requirement for a building. Actually is can be difficult and very expensive to move to a 400 amp service as the utility may have to upgrade cabling and transformers. Utilities will also ask for a load study as described above before considering a 400 amp service

with that said I see no reason you cannot add en EV wall connector. Especially if you schedule it to run in the off hours like late evemings. If you ever have the need for another wall connector pick one that can load share with the other one so they will auto reducing charging currents if two or more vehicle are connected at the same time

good luck

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[moosetags]

We just had our Rivian wall charger installed earlier this week. Our total cost for parts and labor was $3,500. About half of our cost was installing a new exterior circuit breaker box with enough space to accommodate the the new additional 50 amp and 60 amp circuit breakers. We opted to add an additional 50 amp outlet next to the wall charger.

We also have 200 amp service to our 3 story, 3,200 square foot house house. We use natural gas for our water heaters, stove, fireplace logs, and clothes dryer. We have three heat pump a/c units and a 30 amp outlet for our Airstream Travel Trailer which is always plugged in when we are at home.

I would definitely get a second opinion on your electrical issues. Please let us know how this turns out.

Brian

 

[kennyrosen]

I have 3100ft home in Florida, 2 ac units, induction 100 electric as no gas in house. I have 200amp service and installed 60 amp breaker. Never a problem. Skip the upgrade

 

[rtobrien63]

we have a 100 amp line coming to the garage from the house and run a 60 amp circuit breaker. It has been rock solid. I have to adjust the charging amps in the truck (down to 40 amps) when the power goes out and I run a generator or it trips the breaker for the generator

 

[sub]

Finally had a company visit to see about installing the home Rivian charger. They say I need to go to a 400A service because my current potential load is 161A on my 200A service. They sent me a bill for $8,779.95 to upgrade to 400A. I'm very curious if there are other ways to install the charger without going to this much expense.

Just have them install a 30 amp circuit. That will keep you under 200A. I am currently charging two EV's ( Rivian and Tesla) from a single 30 amp circuit and it is more than enough.

It would be a problem if we both drove 200+ miles in one day and then both wanted to do it again the next day. But that is not ever going to happen, and if it did we could just visit a DC charger.

 

[Oldsmobile_Mike]

It’s not very large, it’s 3300sqft.

Sorry for your issues. But man, that's some first world problems. ?

 

[HaveBlue]

My panel is heavily oversubscribed but it means nothing unless there's a load to exceed it. At night, not even my AC is running so the whole panel is essentially idle. Breakers are there to protect wiring and are not an indicator of load. After doing a load calculation spreadsheet with the EVSE figured in I'm still at 80A ampacity. The panel can't physically take bigger than the 50A for the EVSE but it's a gift to be able to have that much without a panel upgrade thanks to quads.

 

[FlightDoc]

Yup 2nd opinion. Getting to 400A is very expensive, not practical for single family house. I had 2 opinions including QMerit both said load calcs are rarely used for 200A houses.
I finally installed the Rivian charger myself and passed inspection no prob.

 

[dradam]

I agree with many above that a second opinion is worth it. I would be surprised if a load calculation done correctly is really 161 of 200 amps on a 3300 sq foot home. The national electric code is conservative -- as it should be. A true load calculation will separate your continuous loads and non continuous loads. It sounds like your electrician may have just added up the totals on the breakers. I would double check on that, that is not how its done.

I have a 90 amp sub panel in my garage that is pretty full, but I have calculated the loads and used a non contact amp meter to confirm them. At max winter or summer that panel will be pulling well under 72 amps (with the vehicle charging) at any given time which is 20% lower than the breaker, as it should be.

Safety is paramount as we all begin to charge really big flammable batteries in our garages, but I am hopeful for you that you first estimate was incorrectly calculated.

Best wishes.

 

[MIG]

We have a larger single-family home with two furnaces/AC units, a 2+HP pool pump, pool heater, 2 refrigerators, an electric dryer and a 60Amp EV circuit on a 200A panel. No issues. Other than a pretty high electric bill (aside from the EV).

 

[Ecupip]

Ya'll rock. Thanks so much for all the great comments and advice!!

Update on my install. While waiting to hear back from the Qmerit installer, our original electrician who wired the house got up with me and stopped by yesterday. He didn't even flinch when I said I needed to add a 60a connection for the charger. He said we would be fine and will never get near the limits of our 200a system, just like many of you said. I should receive the quote to install the charger from them in a day or two.

Also ran across this video last night. I thought the calculation part was nice. I pulled the numbers from the utility of our usage during the past year and we've never been over 102 amps.

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