So I'm going to get a dedicated 240v line installed in the garage. I want to future proof to some degree without going overboard. What are the pros and cons of getting a 30/40/50amp circuit installed? What is the cost benefit of each, considering the possibility of some, as yet unknown, plug-in car in the future?
30, 40 or 50 Amps?
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If you want to future proof...run at least a 60 amp line into a subpanel in the garage, so you can mix and match
???.......
Not completely. But I sure as heck wouldn't install a 20amp circuit because that seems more like a Volt only solution. And a present Volt at that.![]()
The crystal ball says there is no such thing as future proof.
From the point of view from an electrician of 42 years I strongly suggest the following. Install 6/3 AWG with a dual 20 amp breaker and direct wire the power supply without any plug. Everyone is suggesting installing a 50 amp circuit and breaker for a 16 amp load that the Volt requires. This defeats the whole purpose of the breaker which is to protect your car from any unknown over current. In the event that you get a car which requires more current then all that is required is changing out the breaker in the panel.
As for future proofing by getting a 50 amp power supply with a 50 amp breaker in the event that?, maybe?, something might?, happen is rather ridiculous as no one can predict what will happen in the future which in my opinion will be a pulse power supply/charger integrated unit.
Just my .02 cents worth, and this is what I did with a $379 power supply. I left the future proofing money in the bank.
As for future proofing by getting a 50 amp power supply with a 50 amp breaker in the event that?, maybe?, something might?, happen is rather ridiculous as no one can predict what will happen in the future which in my opinion will be a pulse power supply/charger integrated unit.
Just my .02 cents worth, and this is what I did with a $379 power supply. I left the future proofing money in the bank.
tharvey57, this sounds like great advice. Unfortunately it went right over my head
All I know is to ask the electrician to run a dedicated circuit of a certain amperage from the panel to the front of the garage. I may not even buy a Clipper Creek type unit for a while. May or may not get a dongle either since I'm also going to get a dedicated 15amp circuit also which (a non-dedicated version of) currently meets my needs quite well.
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You can choose a 15 amp breaker go in one of the subpanel's slots support a Volt charger you choose now to install now and later add a larger breaker in another slot to support a larger charger unit you may upgrade to in the future for your other EV...and your new cable run is now simple run from the subpanel, rather than having to run it from your main panel, assuming your main panel is in the basement rather than the garage...
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In plain English, put in 6 gauge wire (a tiny bit of future proofing as you won't have to pull new wire if you upgrade in the future) but put in the right sized breaker and plugs for your current EVSE. So don't overbuy the EVSE at this point. I made the mistake of spending double for a 30A instead of a 20A, plus the electrician stupidly put in a 30A circuit, which only safely draws 24A continuously. The wiring in the wall only handles 30A, so if I up my EVSE and car to handle 30A, I will need to rerun a heavier gauge wire to 40A to continuously run 30A. Clear as mud?tharvey57, this sounds like great advice. Unfortunately it went right over my head
All I know is to ask the electrician to run a dedicated circuit of a certain amperage from the panel to the front of the garage. I may not even buy a Clipper Creek type unit for a while. May or may not get a dongle either since I'm also going to get a dedicated 15amp circuit also which (a non-dedicated version of) currently meets my needs quite well.
Since most of the cost of running the dedicated circuit for an EVSE is labor, obtaining any needed permits it makes sense to run a large enough gauge wire that will handle current and future loads. #6 AWG wire should be large enough for your needs but only an electrician can determine the proper wiring based on the distance, load and application. Whether it needs to be a 3 wire configuration 4 wire would depend on the application and codes.
You could have an electrician install a 20 amp breaker now, for the Volt, hard wired to a 20 amp rated EVSE and later change the breaker and the EVSE to handle a larger load. Unless you can envision a special situation such as needing to charge 2 EVs at the same time then installing wiring that would handle up to 60 amp continuous load would probably handle any EVSE eventuality.
120V @ 8 Amp - 2.7 miles EV range recovered per hour of charging (50 miles requires ~ 19 hours)
120V @ 12 Amp - 4 miles EV range recovered per hour of charging (50 miles requires ~12 hours)
240V @ 16 Amp - 12 miles per hour of charging (50 miles requires ~ 4 hours) Note: this is the highest power, fastest rate that the Gen II Volt battery can be charged
240V @ 24 Amp - 18 miles per hour of charging (50 miles requires ~ 3 hours)
240V/@ 32 Amp - 24-25 miles per hour of charging (50 miles requires ~ 2 hours)
You can see that for most people being able to regain 50 miles of EV range (typical US daily commute and other driving) can be completed in from 4 hours to as quickly as 2 hours using a 240V EVSE rated to provide at least 16 amps to the EV's charging system. Unless you need to charge more than one vehicle then any Level II 240V EVSE configuration between 16 Amp and 32 Amp * would meet most EV drivers' needs. Most people would say that they have at least 2 hours of down time when they are at home when they could charge an EV.
* 30 - 32 Amp charging requires a minimum of 40 Amp rated EVSE, wiring and circuit breaker.
You could have an electrician install a 20 amp breaker now, for the Volt, hard wired to a 20 amp rated EVSE and later change the breaker and the EVSE to handle a larger load. Unless you can envision a special situation such as needing to charge 2 EVs at the same time then installing wiring that would handle up to 60 amp continuous load would probably handle any EVSE eventuality.
120V @ 8 Amp - 2.7 miles EV range recovered per hour of charging (50 miles requires ~ 19 hours)
120V @ 12 Amp - 4 miles EV range recovered per hour of charging (50 miles requires ~12 hours)
240V @ 16 Amp - 12 miles per hour of charging (50 miles requires ~ 4 hours) Note: this is the highest power, fastest rate that the Gen II Volt battery can be charged
240V @ 24 Amp - 18 miles per hour of charging (50 miles requires ~ 3 hours)
240V/@ 32 Amp - 24-25 miles per hour of charging (50 miles requires ~ 2 hours)
You can see that for most people being able to regain 50 miles of EV range (typical US daily commute and other driving) can be completed in from 4 hours to as quickly as 2 hours using a 240V EVSE rated to provide at least 16 amps to the EV's charging system. Unless you need to charge more than one vehicle then any Level II 240V EVSE configuration between 16 Amp and 32 Amp * would meet most EV drivers' needs. Most people would say that they have at least 2 hours of down time when they are at home when they could charge an EV.
* 30 - 32 Amp charging requires a minimum of 40 Amp rated EVSE, wiring and circuit breaker.
All good advice, thanks.
My panel is in the garage, so it's only an external wire run across the ceiling to where I want it -- easy. Cost may certainly become an issue after the electrician comes over to look at it. I think no matter what I'm just going to get the outlets installed, not an EVSE. When I'm ready, I'll get a plug-in unit that fits the outlet.
So how long does it take to charge a Bolt or Model 3 with a 30/40 amp circuit? Or maybe I should ask how many miles/hour do you get?
My panel is in the garage, so it's only an external wire run across the ceiling to where I want it -- easy. Cost may certainly become an issue after the electrician comes over to look at it. I think no matter what I'm just going to get the outlets installed, not an EVSE. When I'm ready, I'll get a plug-in unit that fits the outlet.
So how long does it take to charge a Bolt or Model 3 with a 30/40 amp circuit? Or maybe I should ask how many miles/hour do you get?
Thanks jcanoe. It looks like there is no reason at all to go beyond a 40amp circuit for one car.
I take it, that once you have a 40amp outlet, if you get an ESVE it needs to be specific for that outlet. Or are there ways to plug different units into different outlets? That is, if you get a smaller, less powerful, ESVE can it be plugged into a 40amp outlet?
Which Model 3? The long range version can charge at 40 amps (needing a 50 amp circuit) while the short range version can charge at 32 amps (needing 40 amp circuit)
The sr version charges at a max of 30 miles per hour, so about 7 hours. The lr is 37 miles per hour, so full in a bit over 8 hours.
That is from empty. How often do you need to charge from empty? If your commute is 300 miles per day, you may want to move!
Yes you can plug in any Level II EVSE into an outlet as long as the plug specification is the same as the receptacle. My Clipper Creek LCS-20P is rated for 20 Amps but it has a NEMA 14-50 plug. It appears that 40 Amp receptacles are not as common, today, as 30 Amp and 50 Amp receptacles. This is one reason why so many people install a NEMA 6-50 or NEMA 14-50 receptacle for connecting an EVSE. If your electrician determines that you can add a 50 amp breaker to your existing panel and you want the flexibility of having a plug-in type Level II EVSE then installing a NEMA 14-50 receptacle would handle any EVSE up to one capable of providing 40 amps to an EVSE. If you want to go with a hard wired configuration then a 40 amp breaker would be installed for an EVSE that is capable of providing 32 Amp to the EV.
Best analysis so far. Thank you!
So long as the cost is not prohibitive, I guess there's no reason not to install a 50amp circuit with a 14-50 receptacle. That way I could purchase a smaller EVSE now, and still purchase a larger one in the future without having to upgrade the wiring.
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Except, if you install a 50 amp receptacle, a 50 amp breaker, and a 20 EVSE, if the car starts drawing 30-40 amps for some reason, that circuit breaker won't trip and who knows what will happen to the EVSE and the car's onboard charger. The recommendation is to put in the right sized breaker and outlet for the EVSE, but oversized the wiring so you can swap the breaker and outlet later. Alternatively, put in the right sized breaker, outlet, and wiring now and not worry about hoping you guessed right on the wire size. If the next Generation Uber charger turns out to be 80-150A, then all this effort was wasted.
Just for grins and giggles, consider pricing a lower cost alternative, something like a Clipper Creek LCS-20 hardwired, no wall outlet, 20A 240V wiring, and a 20A breaker. Charges Gen 2 at max rate. (obviously not a good approach if you have a BOLT or higher current charging EV in mind for the near future)
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I had #4 Aluminum run to my detached garage, but it's a 900 square foot garage, and I do a lot of woodworking and projects in there. This gives me a 60A-2P circuit breaker at 240V running out there, which is enough for my needs. I had my charger hooked up to a 40A circuit breaker, since my charge is 5' from my garage panel, but for the volt, a smaller breaker would have been fine. The max output on my Siemens charger is adjustable, so I could have gone with a smaller breaker, but it wasn't any significant difference in price. Like most say... it's labor more than the cost of the wire if you are running a small distance.
I'm listening. So how can a 20 EVSE pull more than 20 amps from the breaker, or provide more than 20 amps to the car? Now if the EVSE hiccups and starts drawing more, it would have to go over 50 amps to blow the breaker.
Similarly, if you install a 30 EVSE, what prevents the car from hiccuping and drawing more than 20 amps and creating damage without the EVSE (or breaker) caring?
jcanoe, what's your assessment of this? Do you have this concern with your setup, or are you not worried about this scenario?
Not worried at all. The circuit breaker at the service panel or sub panel is designed to protect the house, house wiring from an overload condition. The EVSE is designed with safety protocols to protect the human operator from being shocked, electrocuted. A relay is used within the EVSE to delay the flow of any current on the two hot leads to the J1772 Connector until the connector is plugged into the vehicle. The EVSE includes ground fault protection and is internally fused. If a condition ever arose that caused the EVSE to start to output more than its maximum rated amperage that internal fuse should open, shut down the EVSE. (This is the same type of risk that we assume with any other home appliance when it is plugged in to a 15 or 20 amp 110V outlet. If there is an overload condition within the equipment then the fuse or breaker within the device will open, else next the circuit breaker at the service panel or sub panel would be tripped, shutting off power to that equipment and the circuit. The device where the overload occurred might be damaged but the home, home wiring would be spared.)
When installing the 240V circuit your electrician is going to want to know what equipment will be plugged into the 240V outlet or wired into the junction box they would be installing. Per the electrical code, for a hard-wired EVSE connection the service panel breaker or sub-panel breaker needs to match the EVSE manufacturer's maximum amperage as stated on the equipment label on the EVSE. So for a Clipper Creek LCS-20 (the wired version of this EVSE), that has a 20 amp maximum rating, it would be correct for the electrician to install a 20 amp breaker in the electrical panel or at the sub panel (if you have one). However, for the plug in version of the same LCS-20 EVSE (in this example an LCS-20P fitted with a NEMA 14-50 plug), the electrical code permits connecting the plug-in EVSE into a receptacle rated higher (but not lower) than the rated maximum amperage of the EVSE. In this case the breaker will match the maximum voltage and amperage of the receptacle. For a NEMA 14-50 receptacle the electrician would be correct to install a 50 amp breaker.
If after installation, inspection you were to change out the 50 amp breaker for a lower amperage circuit breaker to match the maximum amperage rating of the EVSE, for example a 20, 30 or 40 amp breaker, it would be usable with your current EVSE but not correct for the receptacle per the code. If you ever upgraded your EVSE you would also need to change out the breaker at the panel for a breaker with a higher amperage rating not to exceed the 50 amp rating of the NEMA 14-50 receptacle. If you were to later move and don't reinstall the correct 50 amp breaker for the 14-50 outlet the next electrician or owner that attempts to use this 14-50 outlet would have to troubleshoot why the breaker keeps tripping whenever they attempt to operate whatever equipment is expecting 240V/50 amp to be available at the 14-50 outlet, they eventually would find that an under spec breaker had been installed and have to swap this out for the correct 50 amp breaker.
Since you are installing the EVSE inside a garage the plug in type EVSE is allowed by code. The advantages of a plug-in EVSE include: 1) being able to quickly swap out the EVSE for another unit if the EVSE fails. 2) the ability to upgrade to a higher power rated EVSE (up to the maximum rating for the outlet) yourself without requiring the services of an electrician. 3) unplug and take the EVSE with you if you move without requiring that you access, cap off the EVSE wiring inside a junction box. 4) you won't be required to install a separate service disconnect box between the service panel or sub panel and the EVSE as the plug on the EVSE serves as the service disconnect.
(If you were to install the EVSE anywhere outside, i.e. not inside a garage, you would be required to hard wire the EVSE (no plug allowed by code) and install a service disconnect box between the service panel or sub panel and the EVSE. The service disconnect box would need to be installed within line of sight of the EVSE. Although a plug-in EVSE might initially costs slightly more than the wired version of the same model EVSE the cost of installing the required service disconnect box would exceed the additional cost of the plug-in version of the EVSE. There would be no savings, end up costing more to install the wired version of the EVSE because the electrician would have to install a separate service disconnect box in addition to the junction box where the circuit would be connected to the EVSE wiring.)
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