Do I need to run new 400 amp service in my house for the Lightning + everything else?

[personalt]

i am op and have had two electrical contractor review my current set up . Using the nerc rules I don’t have the headroom in my current set up. I have 200 service to my house and my house mostly electric with two 5 ton ac units, electric stove, double oven , washer dryer and pool pump i have head room for 48 amp charger only . The only way I can get the 80 amp which needs headroom of 100 I would have to run a 400 run from the street. The cost been quote $15,000 to $18,000 and that not in the budget. I wanted the platinum ext battery is able to be charged with a 48 charger . I assume I would loose the automatic back up to the house. I just looking for directions.

Did any of these contractors put an AMP meter on the panel and have you run 'all your stuff?' If not they are just guessing. (Unless they went around the whole house and wrote down the values from all the appliance plates and counted lights). You can get a really good idea of usage yourself with a clamp meter for $20 from home depot. Pull the cover, put the clamp meter on one side, turn on the max stuff you think you might run and see what the usage is

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[rjhedrich]

Did any of these contractors put an AMP meter on the panel and have you run 'all your stuff?' If not they are just guessing. You can do this yourself with a clamp meter for $20 from home depot. Pull the cover, put the clamp meter on one side, turn on the max stuff you think you might run and see what the usage is

Yes they did a complete analysis of my electrical box. They were all certified electrical companies and licensed in the state of Nevada. I also paid each a fee to do a complete including using a clamp on each breaker where I had to ramp everything up and each I contracted with said nope the max that can be added is a 60:amp which I had to give up a old rv plug that was set at 50 amp. For me to get the amps I needed my wife would have to give up her electric double ovens and her electric dryer. I would have the cost to run gas lines and by her new appliances .

 

[personalt]

How did the original electricians do the math? Did they go to every AC unit, stove, drier and write down the model numbers and/or find the plates for all the appliances? Did they count all the lights? If they tried to tell you that you need a bigger service just by looking at the service they are full of it. You cant tell the load without going all around the house and writing a ton of stuff down. You can instead be sure their decision was based on 'they will make more money if they sell you a service.

Best thing to do is get a clamp meter, take the cover off, run everything and measure the usage. If you are not even close to maxing out the circuit then you can pay an electrician to do the math to see where you sit by code. If you are already using too much current then dont bother doing the math since you are already over. To be fair, the math in the building code is slightly different than actuality as many things like ACs and ovens state max/startup current on their plates. In the real world example, even if you turn everything on the actual usage will be less then the 'plate values' as things like driers cycle the coil on and off. But by code you need enough power so that the AC can start at the exact same time the oven and drier and firing up their heating elements.

Here is a good video. You can buy a cheaper meter at home depot and it will work fine. lr

 

[personalt]

Yes they did a complete analysis of my electrical box. They were all certified electrical companies and licensed in the state of Nevada.

ok.. if they actually did the math then that is good. A typical electrician (I have a few in my family) will just eyeball it. But still worth doing the clamp meter test that I mention so you can see what your usage is so you can get an idea of what rate you can charge with the existing setup.

 

[toyko joe]

Here is a good reference http://apps.newtonma.gov/apps/test/p/17120253/Load Calculations.pdf

 

[jjwolf]

I have an OpenEVSE for my Mach-E. There is a way (with some effort) of getting them to share the load across multiple chargers so that you don't pop your service feed. There are some other chargers on the market that can cooperate with each other to manage total draw or cycle across them. My house has two 200A feeds, so I'll be installing the second charger on the other service.

 

[EaglesPDX]

40A/240V circuit should be about 9kWh. Enough to charge the battery 80% overnight. On top of the 10-20% starting point (you are not running down to under 10%), fully charged overnight.

Plus you are charging at night when AC loads are low.

Would not waste the $15k.

 

[metroshot]

40A/240V circuit should be about 9kWh. Enough to charge the battery 80% overnight. On top of the 10-20% starting point (you are not running down to under 10%), fully charged overnight.

Plus you are charging at night when AC loads are low.

Would not waste the $15k.

Agree that spending that much for charging is an overkill but that depends on how much electrical load you have.

My current 100A service is fine with the addition of the 80A service because most of our appliances are not electric, no pool pump, no electric appliances, etc...

My electrician said he will upgrade my current 40A EVSE by running a new line from the breaker via 100A sub panel and get me the 100A service.

Cost: $400.

 

[shutterbug]

I have an OpenEVSE for my Mach-E. There is a way (with some effort) of getting them to share the load across multiple chargers so that you don't pop your service feed. There are some other chargers on the market that can cooperate with each other to manage total draw or cycle across them.

From what I read, Pulsar WallBox does best at circuit sharing. Making it fairly easy to share circuit both concurrently and consecutively across several devices.

 

[Hemitoeco]

I’m very curious what the actual install cost of the 80 amp charging station will be. If I’m not mistaken, 80 amp would take a 3 gauge wire? I’m no electrician but running it from my box in the basement to my garage on the other side of the house is going to be a job.

 

[greenne]

I am the OP and went thru all the steps with multiple lis electric pros and all stated I am capped at 60 amps. So I am capped with the 48 amp charger. I am getting the extended battery which will come with the 80 amp unit. Can I install the 80 amp unit and it will downstep to 48 amps or do I need to sell it.

So then here's my question....do you then lose the ability for two way power(i.e. the battery backup) on the Lightning? Do you need to use the full capability of 80A charger to do that, or can you use the 80A charger stepped down to backup?

 

[adoublee]

So then here's my question....do you then lose the ability for two way power(i.e. the battery backup) on the Lightning? Do you need to use the full capability of 80A charger to do that, or can you use the 80A charger stepped down to backup?

Well the home backup system is rated to supply a maximum of 9.6kW or 40A continuous (50A interconnection breaker). I believe zero other details are available on the home backup equipment.

 

[greenne]

Well the home backup system is rated to supply a maximum of 9.6kW or 40A continuous (50A interconnection breaker). I believe zero other details are available on the home backup equipment.

So wondering if you could "step down" the 80A to 40A and be good to go with 2way power..just not charge as fast.

 

[adoublee]

So wondering if you could "step down" the 80A to 40A and be good to go with 2way power..just not charge as fast.

Potentially but this is probably harder to do safely than programming how much an EV draws as a load if the supply circuit is limited. Something adjustable is needed to prevent the Truck/EVSE from toasting the wire that goes back to the panel breaker. The bidirectional charge is likely able to do this functionally, but if user-adjustable this is likely not considered safe enough to depend on. Might need another breaker at the EVSE for the current in "reverse".

 

[greenne]

Potentially but this is probably harder to do safely than programming how much an EV draws as a load if the supply circuit is limited. Something adjustable is needed to prevent the Truck/EVSE from toasting the wire that goes back to the panel breaker. The bidirectional charge is likely able to do this functionally, but if user-adjustable this is likely not considered safe enough to depend on. Might need another breaker at the EVSE for the current in "reverse".

"Well the home backup system is rated to supply a maximum of 9.6kW or 40A continuous (50A interconnection breaker)"

I thought that this meant as long as I wasn't pushing more than 40A (the max from the backup system) I'd be good....the other way I'd be pushing only 40A thru a charger capable of 80A...I would be wired thru a 50A breaker and wires for 40A.

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