What type of 240 V outlet to install for EVSE?

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BuckMkII

Well-known member
Joined
May 6, 2017
Messages
258
Location
Seattle
I'm going to have a consultation/estimate from an electrician about running a 240 V circuit to our garage. We're planning to have this done in two houses, actually, because we may be moving back and forth and would want to take the EVSE with us to whichever location we're currently using. Therefore, hard-wiring it into the wall isn't very attractive. We don't actually own an EVSE yet other than the Nissan OEM level 1.

Which type of 240 V outlet would you have installed, when starting from a clean sheet of paper, and why?
 
Which type of 240 V outlet would you have installed, when starting from a clean sheet of paper, and why?

We recently installed a ChargePoint wifi EVSE and it is required to be hard-wired IF it is to be used at lower amperage (16 or 24A), but can be plugged in if used at higher amperage. Have not figured why yet, but if you like the ChargePoint then make sure that both locations can charge at the higher amperages. Then use the factory recommendations for which plug is needed based on amperage.
 
dmacarthur said:
Which type of 240 V outlet would you have installed, when starting from a clean sheet of paper, and why?

We recently installed a ChargePoint wifi EVSE and it is required to be hard-wired IF it is to be used at lower amperage (16 or 24A), but can be plugged in if used at higher amperage. Have not figured why yet, but if you like the ChargePoint then make sure that both locations can charge at the higher amperages. Then use the factory recommendations for which plug is needed based on amperage.
So for plug-in service, you need a 50 A breaker?

It looks like the most common plug among all the products in your Amazon search is 14-50.
 
BuckMkII said:
I'm going to have a consultation/estimate from an electrician about running a 240 V circuit to our garage. We're planning to have this done in two houses, actually, because we may be moving back and forth and would want to take the EVSE with us to whichever location we're currently using. Therefore, hard-wiring it into the wall isn't very attractive. We don't actually own an EVSE yet other than the Nissan OEM level 1.

Which type of 240 V outlet would you have installed, when starting from a clean sheet of paper, and why?

If it were me I would go with a 14-50 stove plug. Common for EVSE's to have that end. We installed it in centre of the garage. We used a 15 foot 50 amp RV extension cord and vented conduit to get it to the side of the garage we want at any point in time. Different cars charge from different points on the car. The leaf charged from the front etc. Nothing wrong with hardwire but using a stove plug is great for versatility. We have now set our EVSE as permanent and bought a second one for keeping in the car. Tesla EVSE's are cheap. But when we had our leaf we kept a cheap chinese L2 EVSE in the bag.

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A standard NEMA 14-50 with a 50AMP breaker is usually good enough. I just want to remind you of the 80% rule meaning a circuit should not run for long periods of time at more than 80% (short time at max is OK but not hours charging). A LEAF is not capable of passing 80% but other cars on powerful enough EVSEs can. A Tesla wall charger can pull 48AMP with a modern Tesla car so they typically recommend 60AMP breaker. So basically I'd limit to pulling 40amp on a 50amp crrcuit for charging (tesla can limit if ones Tesla can pull that much it varies by model).

Basically are you going to live there a long time, do you want to future proof against capabilities of future cars? I went for 50amp figuring some future 500 mile battery or whatever I'll still just charge at 40Amp (I can limit at my EVSE) and get enough to do around town driving quickly enough. The main cost is the labor if you think you might want to charge faster someday.

A LEAF you could actually put on a 40amp circuit and still obey the 80% rule charging it all out but to avoid confusing a future owner or even yourself in the future I'd just put it on a 50amp.
 
I agree with the above. There are good reasons for using a 40 amp circuit, but if starting from scratch, with no serious financial limitation, the 50 amp circuit and 14-50 RV type plug are the way to go.
 
Here is what the ChargePoint manual says about plugs and amperage:

"Plug-in installation with a 6-50 or 14-50 outlet requires circuits rated 40A or 50A. "


Looks like you get a choice, and the EVSE itself is settable to your amperage.
 
I should have said that the ChargePoint adjustable EVSE can be set to charge at 32 amps for use on a 40 amp breaker, if your wiring sources are limited, and still be plugged in. Below the 32A charging rate it must be hard wired- anyone care to explain why this is?
 
Never heard of a requirement for hard wiring. I know of low amp units from other brands people used on dryer outlets.
As you sound like you are installing a breaker and such is there any reason not to install a NEMA 14-50 outlet on a 50A? The biggest cost is labor.
You don't even need to buy a 40A EVSE you could just plug in a lower amp EVSE with the right plug like the one that came wit the LEAF would work fine.
 
Purchasing a portable L2 EVSE that can be set to provide 240V @ 24A and using that in combination with a NEMA 14-30R (dryer receptacle) saves a fair amount, if the cost of a 50A circuit is too high. In my case, I went with that option as my main panel is only 100A so a panel upgrade would have made for a very expensive project.

The Grizzl-E L2 EVSE can also be set for 24A for use with a 30A circuit.
 
If it is a panel limit I get it. Normally the installation of an outlet or hard wiring a charger as the poster is planning the labor is the big cost. A panel though is a fairly big deal. In your case I'd use a cheaper lower amp charger if they are still sold (16amp bosch for example) or as you say buy an adjustable one and turn down the amps and you are good to go as long as your lines and outlet are good. Sometimes on a l1 outlet in some houses too many may share the circuit depending on appliances you use on that circuit and you can trip or cause heat issues if too much is on that circuit, some have crappy wires too.
 
Unless panelboard capacity is the limiting factor, I strongly recommend a NEMA 14-50 receptacle with 50-ampere circuit breaker and suitable wiring. 14-50 receptacles are common for EVSE's and also for RV's so it is the most compatible for different uses. If panelboard capacity is limited, then you will need to determine the maximum circuit capacity and choose an EVSE of appropriate current capacity with plug connection. Then install a matching receptacle with appropriate circuit breaker and suitable wiring.
 
First order of business should be for the electrician to do load calculations to determine what capacity of additional circuit can be supported by your home's panel and electrical service. In our case we were limited to 20A, unless we wanted to pay for the cost of having the utility run a higher capacity service line to the house.
 
alozzy said:
Purchasing a portable L2 EVSE that can be set to provide 240V @ 24A and using that in combination with a NEMA 14-30R (dryer receptacle) saves a fair amount, if the cost of a 50A circuit is too high. In my case, I went with that option as my main panel is only 100A so a panel upgrade would have made for a very expensive project.

The Grizzl-E L2 EVSE can also be set for 24A for use with a 30A circuit.

I'm supposed to be meeting with an electrician at the older house on Tuesday to discuss feasibility and get an estimate. If the panel needs an upgrade, not really worth it, as you say. That house is on a smallish island, so It's difficult to come up with a 50 mile trip that doesn't start to look like deliberately zigzagging around to add distance egregiously. ANY 240 V system seems pretty generous there!

I was thinking of having the same outlet in both places for compatibility, but it might make more sense to have a high-current circuit in the garage at the primary house, only, if the cost of installation at the secondary house is outrageous.
 
BuckMkII said:
alozzy said:
Purchasing a portable L2 EVSE that can be set to provide 240V @ 24A and using that in combination with a NEMA 14-30R (dryer receptacle) saves a fair amount, if the cost of a 50A circuit is too high. In my case, I went with that option as my main panel is only 100A so a panel upgrade would have made for a very expensive project.

The Grizzl-E L2 EVSE can also be set for 24A for use with a 30A circuit.
I was thinking of having the same outlet in both places for compatibility, but it might make more sense to have a high-current circuit in the garage at the primary house, only, if the cost of installation at the secondary house is outrageous.

Outlet adapters are relatively cheap to purchase or make. I kind of standardized on 2 plugs, the 14-50 for high current charging and the L14-30 locking plug for medium current(24a or less) use. I like the L14-30 for it's portability, the 14-50 is nice but it's a monster plug, not so portable. If you really don't need the extra speed I'd personally just stick with an L14-30 plug and maybe hardwire a higher current EVSE if you want maximum speed.
Note for an EVSE you'd really only need an L6-30 plug but as L14-30's are more common, especially on generators if you ever think you'd charge that way and with an L14-30 outlet you can easily find Y adapters to 2 120v outlets, thats kind of handy.
 
Nubo said:
First order of business should be for the electrician to do load calculations to determine what capacity of additional circuit can be supported by your home's panel and electrical service. In our case we were limited to 20A, unless we wanted to pay for the cost of having the utility run a higher capacity service line to the house.
Yes, the size of the service cable is one of the things I need the electrician to look at. The house has only electric utilities, so I assume it has a fairly large service to run the baseboard heaters, but we'll see.

Long-term, we're wondering if we might be able to add a room (nominally an office) and would probably want a small ductless heat pump system to serve that room and maybe a couple of the other rooms as well. Capacity for that is another question that might affect the available circuit for the car.
 
jjeff said:
Outlet adapters are relatively cheap to purchase or make. I kind of standardized on 2 plugs, the 14-50 for high current charging and the L14-30 locking plug for medium current(24a or less) use. I like the L14-30 for it's portability, the 14-50 is nice but it's a monster plug, not so portable. If you really don't need the extra speed I'd personally just stick with an L14-30 plug and maybe hardwire a higher current EVSE if you want maximum speed.
Note for an EVSE you'd really only need an L6-30 plug but as L14-30's are more common, especially on generators if you ever think you'd charge that way and with an L14-30 outlet you can easily find Y adapters to 2 120v outlets, thats kind of handy.

This is the sort of advice I was looking for! So, you mean have an EVSE with an L14-30 plug and make a 14-50 male to L14-30 female adapter to carry around for use in places like RV parks?

Or at the primary house, where a 14-50 in the garage probably makes more sense, since the primary house is NOT on a small island and someone might want higher capacity some day. OTOH, the primary house is in Seattle, so most destinations are not that far away and charging a new, 200+ mile car to 100% would rarely be needed, if/when we get something more capable than our old Leaf. Maybe even the primary house doesn't need the biggest outlet.

Feel free to shoot down my reasoning.
 
Nubo said:
First order of business should be for the electrician to do load calculations to determine what capacity of additional circuit can be supported by your home's panel and electrical service. In our case we were limited to 20A, unless we wanted to pay for the cost of having the utility run a higher capacity service line to the house.

Last spring I had to change out the panel for my house because I was adding more solar. I pulled the permit and did it myself.

The inspector came and looked at the main lines and said they weren't big enough. We dialed up SCE, because SCE had told me ahead of time they were fine, and they again said the feeds were fine.

The inspector then called his boss, who deferred to SCE. I thought that was a bit funny that SCE won that battle and not the county inspector. Apparently SCE has no issue slightly under sizing the lines coming in. I want to say the rating table had the main lines at 180 amps, so short of the 200 my panel is rated for. (I upgraded from a 100 amp main panel to 200)

Doesn't that make you feel safe?

On the other hand, SCE is probably right and the chance I ever pulled a sustained 180 amps or higher is low. In fact during the day I am putting IN around 6 kW. Probably more during the summer. And the table itself is probably conservative too. Still....



I have a NEMA 14-50 BTW.
 
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