My L1 ESVE findings.....

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Ingineer said:
I fully support DIY efforts like this, but I'd like to issue a warning that this modification as presently implemented defeats the GFCI function of the EVSE and could result in electric shock or death by electrocution in the event of a mishap. EV's are used outdoors, and it's very likely you will at some point connect to something where one or more components are wet. I strongly recommend you do not use any EVSE where the safety has been compromised intentionally. If someone's child plays with your charge cord and gets killed and you knowingly installed a dangerous cord with the safety circuits intentionally bypassed, you could be in big trouble!
You just spent many thousands of dollars on your LEAF purchase or lease, I wouldn't sacrifice a few dollars for safety.
I also think any Electrical Engineers that publish details on how to defeat safety circuits are doing a disservice to their profession and the public in general.
-Phil

Whoa there buddy! I guess you read something different than I did from Jack. He said he will do it WITH the SAFETY features intact which includes the GFI. I think your post is way out of line and premature. Trying to scare people into buying your expensive mod borders on greed and jealousy. And no, you obviously do not support other efforts like this, contrary to your statement. You should be giving him compliments for being able to engineer a simpler, less expensive 240V SAFE EVSE mod. He seems much more professional to me than you do after your premature scathing post.
 
LEAFfan said:
Whoa there buddy! I guess you read something different than I did from Jack. He said he will do it WITH the SAFETY features intact which includes the GFI. I think your post is way out of line and premature. Trying to scare people into buying your expensive mod borders on greed and jealousy. And no, you obviously do not support other efforts like this, contrary to your statement. You should be giving him compliments for being able to engineer a simpler, less expensive 240V SAFE EVSE mod. He seems much more professional to me than you do after your premature scathing post.
Note the "as presently implemented" in my first sentence. Note Jack's own words:
jwallace3 said:
Right now i simply have 240 wired to the J1772 connector. One leg right now is always hot on the connector which obviously isn't ideal, but hey, so is any extension cord that you plug in right? It's not that terrible. The other leg gets closed in when the relay closes and charging begins. Very simple. My above plan is what I intend on doing in the long run for a mod
This is indeed a safety disaster, any other engineer (or almost anyone even remotely familiar with electricity) here will back me up. Note that he wrote "My above plan is what I intend on doing in the long run for a mod". Most definitely unsafe and shame on him for proposing that it's somehow safe, and suggesting that other people perform dangerous acts. He risks litigation and loss of his ability to practice if he is indeed a PE.

There are several other people here working on various EVSE projects which seem sane and well thought out, and I think they are fine to present. (Such as Chris Howell's)

Obviously there are people reading this that don't fully understand the ramifications of bypassing circuits in the EVSE. Even his present circuit including the extra relay STILL eliminates the ground fault detection circuitry in the EVSE!

Since the huge majority of our customers are not about to start taking things apart to save a little money, this is no threat to us. In any event, I welcome the day when EV'ers can walk into any appliance store and buy a nice EVSE for under $100. I personally have designed one that's safe and fully featured, but unfortunately there is not yet a business case until there are more potential customers (read: More EV's on the road). This is why evseupgrade exists, and will exist for a little while longer until economies of scale kick in, costs drop, and there are better and cheaper products on the market, and then we will no longer need to offer upgrades to fill this void.

If a person is qualified to make his own modifications and upgrades, then by all means go for it. Any true engineers will already know how to do it, it's not rocket science here. If you don't fully understand what you are doing, then I cannot recommend you do it, as lethal energy is at play. I've told the people wanting to modify things in their LEAF for various reasons the same thing. It takes a lot of engineering time and testing to verify a system as safe, and it is clear that none of this has been done. A good engineer would never consider altering a system that has not been fully understood, and clearly this is happening here.

-Phil
 
jwallace3 said:
Right now i simply have 240 wired to the J1772 connector. One leg right now is always hot on the connector
Let me, a simple guy, see if I get it? If for some reason, the always hot leg of the supply, comes to energize any portion of the LEAF that is capable of carrying current, or becomes wet and conductive, and you touched that now energized element, whatever it may be, and if you were grounded by by your feet in water, or your hand on a grounded object, YOU would complete the circuit.

This seems especially dangerous in wet and rainy conditions.

On the other hand, I am quite comfortable with my upgraded EVSE, but will still be wearing rubber soled shoes in the rain, and only touching one item at a time with my hands...
 
Wow, I had no idea I could get so much scrutiny and catch so much flack for a simple post of my own personal experiment. Yes, Ingineer, my first step was to turn my ESVE into a glorified extension cord with both legs hot at 240 and one at 120. Who the hell doesn't own an extension cord? Or has ever used one. Not that big of a deal, you plug it up,the other end is hot. That's the way it works. This is not my long term mod plan and I wouldn't ever suggest a design that would hurt or kill someone. Seriously, we all have outlets on the outside of our houses that are exposed to the elements everyday. That is why we have protection circtuits in our houses to take care of that.

I do intend on saving all the features of the ESVE, unfortunately my blackbox approach isn't going to do the trick. I will have to depot my board to reverse engineer circuits to be able to post a safe mod. I understand the SAE and why they have a standard full of safety features, but if you're such a great engineer, and apparently you are, you would notice the standard doesn't allow for portable L2 ESVE. It says "DEDICATED ESVE". According the the SAE standard, all L2 charging should be hardwired and permanently installed as a dedicated circuit. Which means your modified unit is not abiding by the standard, just like any other L2 portable device. We can only say they are based on standards, not designed to adhere to them.

As far as my first "jumper mod" goes, if a person is willing to plug in an extension cord, why can't the jumper mod work for those people? Most rescent houses have GFCI protection on their exterior outlets already. Knowing that the conector would be hot once they plugged it in is no different than any other extension cord. If they understand this and want to do this so that they can spend $10 at lowes and swap out the pigtail then that alowed them to extend their range cheaply. My parents house is 64 miles away. I want to show them the leaf and so my easiest option was this mod. I have a 4 year old and a 4 month old, I'm not worried about it a bit. I use my home blink at home, and in the rare event I need mobile 240 to visit my folks, I have it.

As far as long term plans go, there should be a simpler solution for a mod that includes all of the safety feature, unfortunately I will have to depot to find out whats going on internally. I don't think the CT likes seeing more current than the 12 amps on 1 phase. This is my main problem. At this point I do plan to continue the mod effort, but only to let others know if there is an easy mod. For me it would be easier just to design my own ESVE and remove my J1772 pigtail from the panasonic module. Might even be cheaper to.

My appologies to those I've made mad for some reason, but hey with every great idea comes controversy and backlash.

-ps - please quit putting me down as an engineer. I earned my degree just like any other. With honors, and am a member of IEEE, SAE, and Tau Beta Pi engineering honors society.

For those with kind words, there will be more to come.
 
What's in your head and what you wrote don't seem to be in agreement. Things aren't always interpreted the way you meant too. See Phil's post where he quoted you directly as saying "this is what I plan on doing long term". I'm glad to hear that you don't plan on marketing that solution. I hope you don't think *I* was dissing you as an engineer - I merely wanted to see if I understood things correctly (and it appears I did).

I do agree with you, if someone is cognizant of the risks and is willing to accept them - by all means go for it. Just be careful, especially in inclement weather! You don't want to wind up the recipient of a Darwin award after all!

As for what the standard says, I don't have it in front of me, but others have quoted it here. As I recall it had a clause in it saying something to the effect of "unless specifically designed to be portable". Isn't the SPX EVSE I've seen discussed here both portable and Level 2?
 
jwallace3 said:
As far as long term plans go, there should be a simpler solution for a mod that includes all of the safety feature, unfortunately I will have to depot to find out whats going on internally. I don't think the CT likes seeing more current than the 12 amps on 1 phase. This is my main problem. At this point I do plan to continue the mod effort, but only to let others know if there is an easy mod. For me it would be easier just to design my own ESVE and remove my J1772 pigtail from the panasonic module. Might even be cheaper to.
[\quote]

The CT doesn't seem to mind exceeding 12A. I've often had it pulling 14A+ for extended periods, and there's another person on this board who also measured the same phenomenon.

I agree that for those who know the spec, it's definitely more straightforward to design a new controller from scratch, but it's always a fun intellectual exercise to hack a device into behaving the way you want it to. That's why I find this thread interesting, even though I have no need for a hacked Nissan L1.

I don't want to disparage anyone, but after Ingineer's latest posts, I have to point out that besides the fact that a portable L2 EVSE violates code (although there is debate about this, there are building departments in *some* juridictions that refuse to approve L2 that isn't hard wired), my understanding (please correct me if I'm wrong) is that w/ his 16A mod, the pilot is programmed to allow a 16A draw @ 120V, which clearly exceeds the rated capacity of the NEMA 5-15 plug. I have measured on many occasions the Leaf drawing >12A ... usually around 14A, but sometimes higher. Although it's not 100% reproducible, it sometimes happens when the voltage falls below 110V. So programming a 16A pilot for L1 clearly is not safe.

Please, let's refrain from flaming this gentleman and his experiments. Some of us find this discussion interesting. If you find this thread annoying, you can always ignore it. Perhaps the OP could add a disclaimer to the first post in this thread to warn would be experimenters who have insufficient knowledge about high power circuits "don't try this at home," as the Mythbusters say.
 
jwallace3 said:
Yes, Ingineer, my first step was to turn my ESVE into a glorified extension cord with both legs hot at 240 and one at 120. Who the hell doesn't own an extension cord? Or has ever used one. Not that big of a deal, you plug it up,the other end is hot. That's the way it works.
Not passing any judgement here, but I think what you just said above hits the nail in the head. And based on that, I think this thread should be the retitled as the following:

"How to turn your Panasonic EVSE into a glorified (hot & live) extension cord so it can work with 240V without the built-in safety features, all for only 20 bucks"

This way, people will understand the synopsys of the mod better and see the risk in plain day right up front. Then if they still chose to do copy the mod, they're free to do so.

jwallace3 said:
I do intend on saving all the features of the ESVE, unfortunately my blackbox approach isn't going to do the trick. I will have to depot my board to reverse engineer circuits to be able to post a safe mod.
I'm assuming that after you will have done all this to arrive at a safe mod, you're probably going to end up with a similar mod like Phil did.

I think people would be interested in hearing your conclusion on what you think is needed for a safe mod. Because Phil chose not to disclose the details of his mod (rightly so, for fear of people doing it wrong and messing it up and ruin their EVSE or make it unsafe), many people are very curious about a safe mod, and they're gonna want to know all the details of your findings.

However, I would strongly suggest that you start a new and separate thread to discuss your findings for a safe mod, and keep this thread focused on the topic of the quick and dirty $20 mod. That way, people don't get confused between the safe mod discussion (that's not going to be $20) and the unsafe mod discussion here that costs $20.
 
Volusiano said:
And based on that, I think this thread should be the retitled as the following:
Seriously? :roll:

Chillax. There's been way more space wasted discussing how "unsafe" the mod is than actual content. There's plenty of people who would be interested in this mod knowing it's limitations, and they are very clear.

Lets stop beating a dead horse (pretty much 7 pages worth now) and let's discuss the technical progress instead, eh? Or if you must, let's move that discussion to it's own thread.
 
i say the more options the better.

i also say that until we actually see "something" its tough to evaluate the project. so i say, if you are interested in DIY, check it out.

if you rather pay for someone elses, expertise, there is nothing to wait for since its already here.

this mod is one of many many many that will be coming down the line. take it or leave it. with any DIY project there is always a greater risk
 
drees said:
Volusiano said:
And based on that, I think this thread should be the retitled as the following:
Seriously? :roll:

Chillax. There's been way more space wasted discussing how "unsafe" the mod is than actual content. There's plenty of people who would be interested in this mod knowing it's limitations, and they are very clear.

Lets stop beating a dead horse (pretty much 7 pages worth now) and let's discuss the technical progress instead, eh? Or if you must, let's move that discussion to it's own thread.


Because on the MNL things go on and on and on:) I hope this thread ends and there is one take away, if you are not qualified to work with 240 don't attempt this, qualified means you may at least know ohm's law and have a degree in electronics. I just got a PM from someone that wanted to try this and melted part of their EVSE board because the did not strip the wire length properly and it twisted under strain and crossed. People try this stuff and DIY or not it should not be posted without very big warnings and cautions. Someone will still try this and will likely do it wrong as well, I see this over and over and telling them it about it makes them want to do it. The thread on the Charge America EVSE had pages and pages about people literally being ripped off by that company, testimonials and threats of law suits, crap product, etc, etc. After people actually read all that they still went out and ordered a unit and then were upset when they lost their money and some will do it again. The point is, people are going to do what they want to do without common sense and being responsible about the dangers of electricity is no joke. I also got a PM from someone that bought a J1772 cable and put a 240 plug onto the bare cables, this was an electrician! Don't underestimate what people try, I have seen some crazy stuff and lot's of melted things as well:)
 
1. Yes, the Mod-L1 EVSE by Ingineer does not meet all standards, mostly because ...

2. The un-modified L1 EVSE as made by Panasonic and sold by Nissan does not meet all the J1772 requirements (no diode check).

3. For my info, what SAE "standard" requires hardwire of all EVSEs?

4. Trying to be helpful: NEC 625 specifically DOES allow for design of plug-in L2 (240v) EVSEs. It might be in Section 625.13 if I remember correctly.

5. Of course, the NEC codes are often modified when they are (partially) adopted by different states.

6. Also, local Building Department regulations and customs can vary substantially.
 
This thread has become quite lengthy. Here's the results thus far:

Without depotting the board, I swapped my 120VAC 3 wire pigtail for a 3 wire 240 20 amp cable and connector. Originally I completely bypassed all off the on board relays and GFI CT and wired 240 directly to the J1772 connector and yes it worked. I DON'T RECOMMEND ANYONE TRY THIS AT HOME AND AM NOT RESPOSIBLE FOR ANYONE THAT DOES! This made the end of the connector always hot and if you licked it you could die. But it did work. Next, trying to maintain the safety features of the device I wired one hot and the neutral/ground to the input lugs just like the standard 120 connector and then jumpered the neutral lug to the ground lug going to the J1772 connector. This had to be done because my 240 connector is only a 3 wire, not 4. 4 is more ideal in the even that you have a loose neutral wire. This is why most modern dryer outlets are 4 wire, not 3. Taking my old 120 pigtail, I wired the loose end to a female 240VAC/20 amp connector. And of course this worked the way it was supposed to.

Using a Form C relay I wired the common contact to the J1772 connector, the normally closed contact to the neutral lug that originally went to the J1772 connector (this is after the relays on the board and GFI CT) and then I wired the normally open contact to the second 120 leg looping it through the GFI CT. The coil I wired from the input neutral lug to the second 120 leg, so if no second 120 leg is present for 240 charging, the common is connected to the normally closed contact which is neutral and the L1 charging happens. If the second 120 leg is present the relay closes and common is now connected to the normally open contact which connects the second 120 leg to the J1772 cable while looping through the CT. There is one downside to this and that is that there is a hot leg present on the J1772 connector as soon as it's plugged in. The solution to this would be to connect the neutral side of the relay coil to the ouput lug that originally went to the J1772 connector, only then would the relay close the normally open contact and supply 240 once the ESVE closed the relay on the board to supply hot and neutral. I didn't go this second route as of yet because there were some issues encountered.

Back to results, so with this setup L1 works fine, as soon as my installed relay energizes when 240 is appled, I get a solid red fault light. If I remove the second 240 leg from the CT, I get a blinking Fault led. To see if it was the GFI circuit or some other circuit thats potted in the board that I can't see, I split the problem. I snipped the jumpers which were after the relays and then run through the CT. Then using the output of the relays and bypassing the CT I tried using that route and L1 threw a fault as well as L2. So, my conclusion is that there is another circuit that does some integrity checking which is why I will depot and locate what the deal is so I can report if continuing down this path is possible without tearing your ESVE apart and making a complicated mod. Without seeing any code for the device as well it will make it difficult to "see" exactly what the ESVE is measuring and what the limits are. I will make progress, and it may be slow, but I will report on the findings as they come about.
 
As far as long term plans go, there should be a simpler solution for a mod that includes all of the safety feature, unfortunately I will have to depot to find out whats going on internally. I don't think the CT likes seeing more current than the 12 amps on 1 phase. This is my main problem. At this point I do plan to continue the mod effort, but only to let others know if there is an easy mod. For me it would be easier just to design my own ESVE and remove my J1772 pigtail from the panasonic module. Might even be cheaper to.

For a GFCI application the CT does not care if it is 16 or 12 Amps, it works by measuring the difference of "what's going in" vs. "what's going out"... In both cases, if you do not reroute any current, you should have 12 in 12 out ct reading 0 or 16 in 16 out ct reading 0.
 
Absolutely correct! Very similar to how we use CTs in a bus differential scheme, if the sum of the currents entering and exiting a node are not zero from our measuring points, then current is "leaking" somewhere. I'm not even doing the 16 amp thing yet, just trying to find a safe, lesser expensive 12 amp L2 alternative.

chris1howell said:
As far as long term plans go, there should be a simpler solution for a mod that includes all of the safety feature, unfortunately I will have to depot to find out whats going on internally. I don't think the CT likes seeing more current than the 12 amps on 1 phase. This is my main problem. At this point I do plan to continue the mod effort, but only to let others know if there is an easy mod. For me it would be easier just to design my own ESVE and remove my J1772 pigtail from the panasonic module. Might even be cheaper to.

For a GFCI application the CT does not care if it is 16 or 12 Amps, it works by measuring the difference of "what's going in" vs. "what's going out"... In both cases, if you do not reroute any current, you should have 12 in 12 out ct reading 0 or 16 in 16 out ct reading 0.
 
chris1howell wrote:
I believe the ground check uses the 3rd smaller relay (3rd picture far right) to pass a small current from L1 Hot to ground through a 5k or so resistor. If you listen carefully you can hear a clicking right after connection before the main relays engage. I do not think it is checking to see if Neutral and Ground are tied together only that there is a path to ground. Routing current through the 5k resistor would be enough to cause a ground fault so.... my theory is the EVSE powers the 3rd relay causing current to flow to Ground causing the GFCI to read a fault if so, ground and the GFCI CT coil is good. If ground is bad no current flows and the GFCI does not read a fault and the EVSE goes into Fault state.

tps wrote:
I thought about that, but wouldn't that cause an upstream GFCI outlet which was supplying the EVSE to trip? My calcuation is that 5K would cause 24 mA to flow, which would definitely cause the GFCI to trip out. I'm guessing the current which is injected comes from the secondary of the 20 volt transformer. With this isolated source, they could put current into the ground, splitting the return current equally on the line and neutral, thus allowing a flow of current to test ground continuity while maintaining current balance on the L and N to prevent tripping upstream GFCI.

Edit: Now I think of it, that wouldn't work. Since return current it the same phase in L and N, it would add rather than cancel to zero in the CT core, so it would cause the external GFCI to trip...

Maybe it is a resistance of 100k from hot to ground. That would not trip GFCI but the voltage generated by the CT could be measured to verify that current is passing to ground... Without taking it apart it’s just a guess....
 
I was thinking of something similar to that as well. I would really dig into the standard and probe and make guesses, but I'm at the point where I might as well depot so I can give the folks, who would like to know if this is possible, easy, and inexpensive, some results. If I find that the mod would approach being too difficult for the average person or the cost approaches $50 I will finish the mod, but will then shift gears on designing a portable L1/L2. I'm pretty sure I could get the electronics/components required, minus the J1772 connector, for about $50.
chris1howell said:
chris1howell wrote:
I believe the ground check uses the 3rd smaller relay (3rd picture far right) to pass a small current from L1 Hot to ground through a 5k or so resistor. If you listen carefully you can hear a clicking right after connection before the main relays engage. I do not think it is checking to see if Neutral and Ground are tied together only that there is a path to ground. Routing current through the 5k resistor would be enough to cause a ground fault so.... my theory is the EVSE powers the 3rd relay causing current to flow to Ground causing the GFCI to read a fault if so, ground and the GFCI CT coil is good. If ground is bad no current flows and the GFCI does not read a fault and the EVSE goes into Fault state.

tps wrote:
I thought about that, but wouldn't that cause an upstream GFCI outlet which was supplying the EVSE to trip? My calcuation is that 5K would cause 24 mA to flow, which would definitely cause the GFCI to trip out. I'm guessing the current which is injected comes from the secondary of the 20 volt transformer. With this isolated source, they could put current into the ground, splitting the return current equally on the line and neutral, thus allowing a flow of current to test ground continuity while maintaining current balance on the L and N to prevent tripping upstream GFCI.

Edit: Now I think of it, that wouldn't work. Since return current it the same phase in L and N, it would add rather than cancel to zero in the CT core, so it would cause the external GFCI to trip...

Maybe it is a resistance of 100k from hot to ground. That would not trip GFCI but the voltage generated by the CT could be measured to verify that current is passing to ground... Without taking it apart it’s just a guess....
 
jwallace3 said:
I was thinking of something similar to that as well. I would really dig into the standard and probe and make guesses, but I'm at the point where I might as well depot so I can give the folks, who would like to know if this is possible, easy, and inexpensive, some results. If I find that the mod would approach being too difficult for the average person or the cost approaches $50 I will finish the mod, but will then shift gears on designing a portable L1/L2. I'm pretty sure I could get the electronics/components required, minus the J1772 connector, for about $50.
You've seen chris1howell's DIY EVSE project thread, right?
 
I have read some of it and remember seeing it a while back. It's all just for the heck of it. I know this thread got out of control quick, but I did mention early on I'm mentoring 2 EE seniors in their senior project, which is to design a portable L1/L2 ESVE so I will probably do it even if I get the mod to work, just so I am forced to go over the standard with a fine tooth comb and be able to help the students define their specifications and solidify their design.

drees said:
jwallace3 said:
I was thinking of something similar to that as well. I would really dig into the standard and probe and make guesses, but I'm at the point where I might as well depot so I can give the folks, who would like to know if this is possible, easy, and inexpensive, some results. If I find that the mod would approach being too difficult for the average person or the cost approaches $50 I will finish the mod, but will then shift gears on designing a portable L1/L2. I'm pretty sure I could get the electronics/components required, minus the J1772 connector, for about $50.
You've seen chris1howell's DIY EVSE project thread, right?
 
jwallace3 said:
I have read some of it and remember seeing it a while back. It's all just for the heck of it. I know this thread got out of control quick, but I did mention early on I'm mentoring 2 EE seniors in their senior project, which is to design a portable L1/L2 ESVE so I will probably do it even if I get the mod to work, just so I am forced to go over the standard with a fine tooth comb and be able to help the students define their specifications and solidify their design.
Right - I was only pointing it out in case you hadn't seen it and knew that he already has a DIY EVSE control module in case you wanted to use that as a starting point for your own design or depending on the level of the students give them something to build from if going down the build from scratch route. :)
 
Back
Top