questions about supplied 30 amp leaf 2018 EVSE

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dylorama

New member
Joined
Jul 17, 2018
Messages
4
Hi there

New to the forum. I am getting my 2018 leaf at the end of august, just in time (hopefully) to sneak in the Ontario EV rebate. I have some questions about level 2 charging that I have not been able to find answers to. I am currently in a rented house, so I am reluctant to fork out for any funds to install any dedicated level 2 charging equipment. My plan is to use level 1 charging almost exclusively, and on the odd time when I would not be able to charge to 100% the night before some serious driving, simply use a level 2 with a beefy RV extension cord from either the stove or dryer plug. I’m confident that with a reasonable amount of planning this will fully meet my family’s driving needs.

Because the on-board charger is limited to 6.6 KW (27.5 Amps at 240 Volts), I had decided that a 24 Amp Nema 14-50 EVSE would be best. Coupled with a 14-50 to 14-30 adapter, I would be able to safely plug into any dryer or stove outlet (for example if staying at a friend’s place out of town) without drawing too much power. Yes, I would not be getting the most I could from a 50 or 40 amp circuit (by 3.5 amps), but I would also have the flexibility to safely use 30 amp circuits as well. Makes sense to me.
I was surprised to learn then, that the Leaf comes with a 30 amp 14-50 EVSE. Completely goes against what I thought was a completely logical compromise, given the limits of the on-board charger.

So now my questions:

When almost all 240 volt plugs in north America are either 30, 40, or 50 amps (for a draw of 24, 32, or 40 amps), why would they put in a charger that tops out at 27.5 amps? Why not match one of those standards? Is there a non-north American context I don’t know about?

Why supply an EVSE that does not match the on-board charger? And, does this thing try to draw 30 amps, but tops out at 27.5 amps, or is it rated at 30 amps and will only safely draw 24 amps (80%)?

Following up on the last question – With a 14-50 to 14-30 adapter, would I be able to use the included EVSE with a 30 amp dryer outlet? If it draws 24 amps (80% of 30), then yes, but if it draws 27.5 amps then maybe, but probably not safely, and definitely not within the specifications of a nema 14-30 circiut.

Anyway, that’s it. Any insight would be greatly appreciated.
 
Because car makers are generally clueless about charging and Nissan in particular. The design of the new cable they made demonstrates this clearly.
 
If you want to use an existing dryer outlet, it's likely plugged into a NEMA 14-30R. However, the OBC on the LEAF will pull 27.5A and that can't be adjusted on the car.

So, you'll need to either purchase an EVSE that will limit the charging rate to 24A (the Zencar 32A portable EVSE will do that), or you'll need to use the stove receptacle (likely NEMA 14-50R), in which case you can use the stock EVSE.

Note that older receptacles may not match the above specs, so you need to check before purchasing any EVSE.
 
I should have mentioned that, on the 14-50 plug of my Zencar 32A EVSE, I removed the neutral blade as the EVSE doesn't use the neutral and that let's me plug into either a 14-30R or a 14-50R.

I also made an adapter cable (be very careful and don't use RV adapters as they aren't wired correctly) that let's me charge on a TT-30R (120V @ 30A) at campgrounds, or on a standard 120V receptacle too - all with the same Zencar EVSE.
 
Actually, the current that the onboard charger draws depends upon the supply voltage and battery state of charge. It is about 27 amperes at 240 volts, about 26.8 amperes at 242 volts, and lower if the voltage is higher. It will draw 30 amperes at 212 volts and could go up to 32 amperes (based upon specifications published in the 2015 owner manual). In all cases, the current drops as the battery approaches full charge. I consistently see 30.0 amperes when I charge at my workshop at about 212 volts. So far, the voltage has never dropped enough to cause the current to go higher

You could use the Nissan EVSE with a 14-50 range receptacle and RV extension cord, but not with a 14-30 dryer receptacle at 240 volts. There are other threads which document that the Nissan EVSE will not work on 208 volts. If you need to charge from dryer receptacles or on 208 volts, you will need a different EVSE.
 
Just my experiance...i ran a 30 amp dedicated circuit for my 2018 leaf yesterday...it tripped after about 10 mins of charging, so i grabbed my amp meter and flipped it back on
pm3CORGzj
31.4 amps... also very hot to the touch...i would HIGHLY reccomend 8gauge wire, 40 amp dedicated plug for charging these vehicles...especially in hot climates because they are obviously capable of drawing WAY more than the claimed 27~a i keep seeing thrown around on this thread
 
The 27.5A you see is based on this:

240V * 27.5A = 6.6 kW (supposedly what the OBC draws)

This, of course, doesn't account for loses. So, based on what you are seeing on your amp meter, the losses must be close to 4A. I'm surprised losses are that high, but it's likely because the wire gauge is too light.

If you intended to charge at 30A, I'm not sure why you put in a 30A circuit. On a 30A circuit, I personally wouldn't exceed 24A (with my Zencar 32A portable EVSE, I use a 30A circuit but I set the amperage to 24A - the cable never gets even warm).
 
Are you sure you won't be getting a dual voltage EVSE with the car? It comes with QC package in S, or Tech package in SV or standard with SL

As far as voltages goes; its an international car so they could tailor it for each country (which they do to a point) or do a one size fits all to lower costs.
 
alozzy said:
The 27.5A you see is based on this:

240V * 27.5A = 6.6 kW (supposedly what the OBC draws)

This, of course, doesn't account for loses. So, based on what you are seeing on your amp meter, the losses must be close to 4A. I'm surprised losses are that high, but it's likely because the wire gauge is too light.

If you intended to charge at 30A, I'm not sure why you put in a 30A circuit. On a 30A circuit, I personally wouldn't exceed 24A (with my Zencar 32A portable EVSE, I use a 30A circuit but I set the amperage to 24A - the cable never gets even warm).

2018 EVSE is plenty heavy enough. Losses should be less than 10%
 
Solarninja said:
Just my experiance...i ran a 30 amp dedicated circuit for my 2018 leaf yesterday...it tripped after about 10 mins of charging, so i grabbed my amp meter and flipped it back on
pm3CORGzj
31.4 amps... also very hot to the touch...i would HIGHLY reccomend 8gauge wire, 40 amp dedicated plug for charging these vehicles...especially in hot climates because they are obviously capable of drawing WAY more than the claimed 27~a i keep seeing thrown around on this thread

If you have a 240V Nissan EVSE it needs to be on a 50A 14-50 outlet with a 50A breaker by code in most municipalities of the USA and likely Canada as well. You should never have this EVSE on a 30A circuit and you really should hire a professional to inspect your wiring as it never should have been on the wrong circuit type.
 
EVDRIVER said:
If you have a 240V Nissan EVSE it needs to be on a 50A 14-50 outlet with a 50A breaker by code in most municipalities of the USA
A 14-50 receptacle on a 40A circuit is more usual for a 30A EVSE and is NEC compliant.

Cheers, Wayne
 
EVDRIVER said:
Solarninja said:
Just my experiance...i ran a 30 amp dedicated circuit for my 2018 leaf yesterday...it tripped after about 10 mins of charging, so i grabbed my amp meter and flipped it back on
pm3CORGzj
31.4 amps... also very hot to the touch...i would HIGHLY reccomend 8gauge wire, 40 amp dedicated plug for charging these vehicles...especially in hot climates because they are obviously capable of drawing WAY more than the claimed 27~a i keep seeing thrown around on this thread

If you have a 240V Nissan EVSE it needs to be on a 50A 14-50 outlet with a 50A breaker by code in most municipalities of the USA and likely Canada as well. You should never have this EVSE on a 30A circuit and you really should hire a professional to inspect your wiring as it never should have been on the wrong circuit type.
By code a 14-50 outlet can be on a 40a circuit with 40a wiring, personally I'd label the outlet with a sticker that stated such though. Also a 40a circuit/wiring should be just fine for a Leaf charger, even if it drew 32a, it would be within the 80% rule. 30a is just too low though, even at 27.5a(which is what my '13S Leaf maxes out at) your wiring/breaker will get warm after extended use. I use such a setup at work for short-term charging but am very conscious about limiting my charging time, I wouldn't even to attempt charging if my Leaf approached 30a or more.
Whitney snuck in while composing my post, and of course he's correct :)
 
jjeff said:
EVDRIVER said:
Solarninja said:
Just my experiance...i ran a 30 amp dedicated circuit for my 2018 leaf yesterday...it tripped after about 10 mins of charging, so i grabbed my amp meter and flipped it back on
pm3CORGzj
31.4 amps... also very hot to the touch...i would HIGHLY reccomend 8gauge wire, 40 amp dedicated plug for charging these vehicles...especially in hot climates because they are obviously capable of drawing WAY more than the claimed 27~a i keep seeing thrown around on this thread

If you have a 240V Nissan EVSE it needs to be on a 50A 14-50 outlet with a 50A breaker by code in most municipalities of the USA and likely Canada as well. You should never have this EVSE on a 30A circuit and you really should hire a professional to inspect your wiring as it never should have been on the wrong circuit type.
By code a 14-50 outlet can be on a 40a circuit with 40a wiring, personally I'd label the outlet with a sticker that stated such though. Also a 40a circuit/wiring should be just fine for a Leaf charger, even if it drew 32a, it would be within the 80% rule. 30a is just too low though, even at 27.5a(which is what my '13S Leaf maxes out at) your wiring/breaker will get warm after extended use. I use such a setup at work for short-term charging but am very conscious about limiting my charging time, I wouldn't even to attempt charging if my Leaf approached 30a or more.
Whitney snuck in while composing my post, and of course he's correct :)


Code varies in every municipality so 40A breaker is not code on all 14-50 outlets as a device that draws 40A would not be derated by 20%. You can't have a Tesla 40A continuous EVSE on a 40A breaker.
 
EVDRIVER said:
Code varies in every municipality so 40A breaker is not code on all 14-50 outlets as a device that draws 40A would not be derated by 20%. You can't have a Tesla 40A continuous EVSE on a 40A breaker.
I'm not aware of any municipality whose written rules would disallow a 14-50 receptacle on a 40 amp breaker for a 32 amp continuous or 40 amp non-continuous load. That would be an odd amendment to make to the NEC. Can you provide an example?

You are correct that a 40A continuous EVSE should not be plugged into a 40 amp circuit, although if everything is installed correctly, the worst that will happen is that the breaker will nuisance trip.

If I recall correctly, older Tesla UMCs would default to 40 amps continuous when used with a 14-50 plug; if there was not an easy option to configure the UMC to 32 amps for the case of a 40 amp circuit with 14-50 receptacle, that was a failing on the part of Tesla.

Cheers, Wayne
 
EVDRIVER said:
jjeff said:
EVDRIVER said:
If you have a 240V Nissan EVSE it needs to be on a 50A 14-50 outlet with a 50A breaker by code in most municipalities of the USA and likely Canada as well. You should never have this EVSE on a 30A circuit and you really should hire a professional to inspect your wiring as it never should have been on the wrong circuit type.
By code a 14-50 outlet can be on a 40a circuit with 40a wiring, personally I'd label the outlet with a sticker that stated such though. Also a 40a circuit/wiring should be just fine for a Leaf charger, even if it drew 32a, it would be within the 80% rule. 30a is just too low though, even at 27.5a(which is what my '13S Leaf maxes out at) your wiring/breaker will get warm after extended use. I use such a setup at work for short-term charging but am very conscious about limiting my charging time, I wouldn't even to attempt charging if my Leaf approached 30a or more.
Whitney snuck in while composing my post, and of course he's correct :)


Code varies in every municipality so 40A breaker is not code on all 14-50 outlets as a device that draws 40A would not be derated by 20%. You can't have a Tesla 40A continuous EVSE on a 40A breaker.
I believe the reason you can put a 14-50 outlet on a 40a circuit is that there isn't a NEMA 40a 240v outlet, outlets go from 30a to 50a.
 
EVDRIVER said:
Code varies in every municipality so 40A breaker is not code on all 14-50 outlets as a device that draws 40A would not be derated by 20%. You can't have a Tesla 40A continuous EVSE on a 40A breaker.

I suppose nothing is absolutely code in EVERY municipality, but using a 50a receptacle on a 40a circuit for a 30/32a EVSE is a very common install method. It depends on the rating of the EVSE, which in the case of the Nissan is 30a, so a 40a circuit is fine. I would personally put in a 50a circuit if I had it to do again, but if you hand the Nissan EVSE to an electrician and just say, "install it" I bet they install a 40a circuit every time. Nothing wrong with that and there are many circumstances that would even make that desirable, like existing wiring, a long run where the cost difference is significant, or panel capacity issues.
 
davewill said:
EVDRIVER said:
Code varies in every municipality so 40A breaker is not code on all 14-50 outlets as a device that draws 40A would not be derated by 20%. You can't have a Tesla 40A continuous EVSE on a 40A breaker.

I suppose nothing is absolutely code in EVERY municipality, but using a 50a receptacle on a 40a circuit for a 30/32a EVSE is a very common install method. It depends on the rating of the EVSE, which in the case of the Nissan is 30a, so a 40a circuit is fine. I would personally put in a 50a circuit if I had it to do again, but if you hand the Nissan EVSE to an electrician and just say, "install it" I bet they install a 40a circuit every time. Nothing wrong with that and there are many circumstances that would even make that desirable, like existing wiring, a long run where the cost difference is significant, or panel capacity issues.

Yes it is however there is no way to insure what is plugged into that outlet. I have seen more than one inspection failed for that reason. In some areas EV charging installations require special permits even when it's only a 240V outlet. Inspectors also make a call on site as to what they deem is ok. I have seen very liberal to insanely strict. Since a 14-50 is an outlet and not hard wired there is no way to determine what loads may be plugged in. In cases where a 50A circuit can be run it makes more sense, additionally tripping a breaker is not the only side effect of running a breaker at it's full value, the 20% rule helps keep connections from failing over time from heat, this is why there are special breakers with better connectors for continuous use at their full rated value. These are rarely used as it is easier to follow the general rules for derated circuits. I was just on an inspection this week and the inspector was so relaxed about everything and yet a month ago the guy went though every wire in the panel and even read every wire size, he almost failed the inspection for some sensor wires until he saw they were rated for 600V. Really depends where you live and who you get, fridays are good days to schedule inspections FYI:)
 
EVDRIVER said:
Inspectors also make a call on site as to what they deem is ok.
One does have to watch out for inspectors who make up their own rules. Unless the rule is adopted in writing by the jurisdiction, or a reasonable interpretation of the text of the NEC, it is not valid. If necessary, I would politely challenge an inspector who told me that I can't put a 14-50 receptacle on a 40 amp circuit.

EVDRIVER said:
additionally tripping a breaker is not the only side effect of running a breaker at it's full value, the 20% rule helps keep connections from failing over time from heat, this is why there are special breakers with better connectors for continuous use at their full rated value.
Certainly continuous use will out any poor connections. But otherwise, the breaker is the only part of the circuit not rated for continuous use at100% of its rating. The 100% rated breakers you mention (breakers that can be used continuously at their full rating) prove this point: when using a 100% rated breaker, no other upgrades to the circuit are required to operate at 100% of the breaker rating.

To my knowledge, the differences between a 100% rated breaker and a regular breaker are primarily in the enclosure (and the enclosure is part of the 100% rating). I believe that the UL testing for any breaker requires it to hold at 100% of its rated current under test conditions, out in the open. An enclosure for a 100% rated breaker will hold only one breaker and will have been tested to ensure an adequate rate of heat rejection. That is a vastly different thermal environment than a load center, where multiple breakers are installed in close proximity, and where the 80% maximum continuous current rule applies.

For EVSE installations, 100% rated breakers are not available, as I don't believe anyone makes them smaller than 200A. Their value comes in larger installations, where the cost of the wiring dominates, and the savings from using a conductor at 100% of its ampacity outweighs the extra cost of the breaker.

Cheers, Wayne
 
I don't know how many electrical inspections you have been on and how many times you have challenged and inspector but best of luck with that, it often does not end well. There are plenty of things inspectors push back on and why argue when it's so easy in this case to comply. I have 20 plus years of experience in residential construction and challenging an electrical inspector for something like this can lead to a job site nightmare. Been there, won't do that for a trivial matter like this that would run red flags al over the job or residence.
 
EVDRIVER said:
I don't know how many electrical inspections you have been on
Maybe six? I could be off by one or two.

EVDRIVER said:
and how many times you have challenged and inspector but best of luck with that, it often does not end well.
If your experience has been that it "often" hasn't ended well, and you've approached them politely, then I'm sorry that you are stuck with such bad inspectors.

Cheers, Wayne
 
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