# Testing of EVSE



## Wenyi (Aug 20, 2014)

Hello,

I'm an undergraduate from a local university of Singapore and I'm currently working on my final year project, building of a electric car. My part in this project is to handle all charging related issues; EVSE, on board charger etc.

However, I'm an undergrad major in mechanical engineering and have little knowledge on electrical problems. Thus, I hope I can get help from the members here who has experience building an EV.

Currently I wish to do a test on my EVSE and AVC2 and i've came across online that i'll need an EV simulator to complete the circuit for testing. 

However the explanation was brief and I could not understand how exactly should i come about fabricating this EV simulator.

And I'm not sure of the wiring connections between the AVC2, EVSE and EV simulator. I've came up with a simple schematic myself, but i'm not sure if its correct.


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## PStechPaul (May 1, 2012)

You might want to look for the thread about the DIY EVSE "Juice Box" made by EMW, although it and the 10/12 kW charger do not adhere to the J1772 specification. I drew up a schematic of my own idea for an *EV charger* that should be able to implement the pilot signals *to the EVSE.* This does not show the safety interlocks needed to avoid having exposed "hot" terminals, or disconnection under power:










Here is a PDF that is clearer:
http://enginuitysystems.com/files/EMW/EV_Charger_PCB.pdf

Some other info that might help:
http://www.instructables.com/id/DIY-J1772-EVSE/
http://modularevpower.com/J1772_EVSE.htm
http://en.wikipedia.org/wiki/SAE_J1772
https://code.google.com/p/open-evse/wiki/J1772Basics


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## Wenyi (Aug 20, 2014)

I'll take a look at it. Thanks!


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## Caps18 (Jun 8, 2008)

This is what you are trying to do.

Keep in mind that international color codes for wires are different. And the Chinese charger I have uses the international standard Blue, Brown, and Green/Yellow instead of what the instructions below say.

Here are the instructions for the AVC2:
http://modularevpower.com/Images/avc1/AVC2%20instructions%201_2.pdf

The N.C and C relay is used as a safety switch to prevent the vehicle from moving while plugged in.

The Pilot and Proximity wires make sure the plug is not powered up and energized until it has made a secure connection.

I'm not really sure what it needs to simulate. The charger is what gets connected in your diagram next (instead of EV simulator) and the battery voltage should go up which is the next thing that is attached. There will be a shunt in line with the negative cable between the charger and batter to keep track of how much power goes in, if you want a smaller display that isn't a laptop hooked to the charger. And a big fuse and emergency disconnect for maintenance. Your red lines are wrong though. Try again. I've posted the correct answer as a full vehicle wiring diagram you can search for under my username.


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## Wenyi (Aug 20, 2014)

Hi,

Thank you so much for your reply, it helps a lot in my understanding to the circuit. 

Can I check with you say if I want to 'play' around with the AVC2 and a power source(battery) without the presence of a charger or EV simulator, how do i come about doing it? do I need equipments such as a multi-meter etc?

My objective here is to familiarise myself with the AVC2, doing a very short test on the AVC2 with some simple equipment.


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## Wenyi (Aug 20, 2014)

Hi people,

I've made some minor changes to my schematic, but i'm not sure if it's right so pls correct me if i'm wrong  

theres a few questions i need to clarify:

i) I've placed a fuse in the diagram and i'm not sure if it works this way.

ii) referring to the previous reply, it was said that the negative lines of the charger and battery are connected to a shunt, placed between them. Is it possible for me to exclude the shunt in my circuit?

iii) If its possible to exclude the shunt, do i connect the negative line of the battery to the negative of charger directly?

Thank you!


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## PStechPaul (May 1, 2012)

I think you may be confusing the EVSE with the vehicle battery pack charger. As far as I know, the EVSE only supplies a raw AC or DC power source, possibly with current limiting, but is not meant to be connected directly to the battery pack. The vehicle should have its own charger, which can accept a variety of voltages from 120-240 VAC and as much as 300 VDC, and this is connected to the battery with a buck converter to provide the current required.

The schematic I showed was actually for an EV charger. My idea for an EVSE like the JuiceBox is:










http://enginuitysystems.com/files/EMW/EVSE PCB.pdf


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## Caps18 (Jun 8, 2008)

I think he is just trying to hook up the J1772 charging system, not really construct one from component parts. 

Your fuse is in the wrong place. The EVSE device will protect the connection to the plug and charger. The big fuse needs to be on the wire after the charger and before the multimeter in your picture. There needs to be a smaller 5A automotive blade fuse inbetween the 12V battery positive wire and the AVC2. You are also missing a black wire from the 12V battery. And there needs to be a wire connecting the GND to the CH on the AVC2.


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## Wenyi (Aug 20, 2014)

Hi all, 

I've manage to come out with a new schematic diagram and i hope this time i have got it right. i've tested the schematic diagram with an EVSE, however charging did not work. There is a red '!' light flashing on the EVSE, I've check the circuit and am pretty sure that they are correct. In addition, the proximity led on the AVC2 lighted up, so I'm assuming the circuit doesn't have a problem. 

I've attached a picture of my schematic diagram, an actual connections of my schematic (less the onboard charger, HV battery and 12V lead-acid battery) and lastly a picture of our EVSE.

Currently, I need to troubleshoot and locate the problem in my circuit but i have no idea where to start. 

Any advices on how should I come about troubleshooting this circuit?


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## dougingraham (Jul 26, 2011)

What does the wattstation manual say the flashing ! means?


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## Caps18 (Jun 8, 2008)

It looks like you have everything wired up correctly in that picture. Or at least it matches how I have mine wired, and mine turned on.

Could it be a problem on the inside of the EVSE?


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## Wenyi (Aug 20, 2014)

From the manual it shows that the problem I'm facing is 'Overvoltage/Undervoltage Faults' as this is the only fault that will result in a blinking red fault light whereas the other faults mentioned will produce a solid red fault light.

Quoted from the manual, 'WattStation monitors line voltage and cuts power to the EV if the voltage goes out of range. After one (1) minute, it rechecks the voltage and will automatically re-enable charging if the voltage returns to an acceptable range. The fault indicator will illuminate as blinking red.'

Where should i start my troubleshooting at?

Thanks in advance!


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## dougingraham (Jul 26, 2011)

Wenyi said:


> From the manual it shows that the problem I'm facing is 'Overvoltage/Undervoltage Faults' as this is the only fault that will result in a blinking red fault light whereas the other faults mentioned will produce a solid red fault light.
> 
> Quoted from the manual, 'WattStation monitors line voltage and cuts power to the EV if the voltage goes out of range. After one (1) minute, it rechecks the voltage and will automatically re-enable charging if the voltage returns to an acceptable range. The fault indicator will illuminate as blinking red.'
> 
> ...


The wattstation wiring to the residential panel is where I would look. From your description it thinks your power is out of range. This error has nothing at all to do with the stuff in your car. You do have it connected to a paired 40 amp breaker on opposite phases so the EVSE is seeing 240 volts and the ground wire hooked up right?

I suppose an excessive load on the charger could cause this after it starts but I doubt it even turns on power to the car or you would have mentioned this. And the EMW charger which is what I believe the picture is of takes about 15 seconds minimum to start to ramp up so you should have power to the charger for at least 10-15 seconds before the watt station would see enough load to cause it to trip out.

Know anyone who has a car you can test the EVSE on? Leaf or volt?


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## Wenyi (Aug 20, 2014)

Hi,

Thanks for the help, really appreciate it. You've mentioned about the power from the residential panel, I've also looked into it as well and realised that the frequency from the wall output does not tally with the operating frequency of the EVSE. The frequency from the wall output is 50 hz whereas the operating frequency of the EVSE is rated at 60 hz. 

Could this be the main problem why charging didn't work in my situation?


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## dougingraham (Jul 26, 2011)

Wenyi said:


> You've mentioned about the power from the residential panel, I've also looked into it as well and realised that the frequency from the wall output does not tally with the operating frequency of the EVSE. The frequency from the wall output is 50 hz whereas the operating frequency of the EVSE is rated at 60 hz.
> 
> Could this be the main problem why charging didn't work in my situation?


I suppose it could be a 50/60hz thing but it seems like it would be shortsighted to design a device like this and make it sensitive to frequency when much of the world operates on 50hz. I would expect that it is objecting to the input voltage or perhaps not being wired correctly. Whoever sold it to you should be able to tell you if it is compatible. I remember seeing photos of the inside of one of those from a couple of years ago and it seems like there were dip switches or some other way to make configuration changes.

Talk to the vendor and make certain it is wired up correctly.


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## Caps18 (Jun 8, 2008)

If you are using a North American Wattstation that is looking for 240V/60Hz power it is different than Asian 230V/50Hz power. I learned the hard way at my first job that international 230V is 230V on the hot leg and 0V on the neutral, where 240V in the USA means 120V on the hot leg and 120V on the neutral leg.

International 230V power
Hot: 230 V
Neutral: 0V
Ground: 0V
50Hz

And USA 240V power is:
Hot: 120V
Hot: 120V
Ground: 0V
60Hz

I have never seen a US240V to International230V transformer, but it isn't to say they don't exist. I would think they would cost more than a new EVSE made for Asian 230V power if that is the cause of your problem.

http://www.practicalmachinist.com/v...erters-vfd/european-vs-usa-240v-power-208785/


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## Wenyi (Aug 20, 2014)

Hi all,

Thanks for your advices, I'll take note of them. I've already emailed the manufacturer for a clarification, hopefully i'm able to configure the settings in the EVSE to match the wall output i have here.

Thanks once again!


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## Wenyi (Aug 20, 2014)

Hi all,

something came across my mind when we were discussing about the compatibility of the EVSE to the wall power supply I have here in Singapore. As discussed, the reason why i can't charge my charger via my EVSE may be because of the mismatch of the frequency of the EVSE and wall power supply; EVSE operating at 60 hz whereas the wall power supply only produces 50 hz. 

These mismatched characteristic may have caused my charging process to not work.

Can i check with you guys if the same logic applies to the charger as well? I have a smartcharge 12000 and I'm wondering if there will be any mismatch of properties between the charger and the wall power supply i have in Singapore.


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## dougingraham (Jul 26, 2011)

Wenyi said:


> Can i check with you guys if the same logic applies to the charger as well? I have a smartcharge 12000 and I'm wondering if there will be any mismatch of properties between the charger and the wall power supply i have in Singapore.


The charger should be fine. There is no reason you cant fit a regular cord to the charger and just plug it into an outlet. The display will light up and the fans will come on and you can fiddle with the settings via the pushbuttons.

The EVSE is nothing more than a fancy power switch. The whole point of it is protection of people when making and breaking the connection to the vehicle. The error you are seeing is another kind of protection. If the charger pulls more power than the wiring up to the EVSE can take the wires between the fuse box (circuit breakers) and the EVSE will get hot. The EVSE can sense this because the voltage will drop. So an excessive low voltage will be one thing that could trigger the alarm you are seeing. Another thing that can cause an EVSE to trip out is if it senses a current in the ground wire. This will happen if either of the hot leads somehow gets connected to the ground wire in the EVSE cable. This would occur only after the EVSE wakes up and the charger has started and should have a different kind of fault indication on the EVSE. This current required here is very small, on the order of a few ma.

If you have access to a car that you know works with an EVSE then plug your EVSE into that car and see if it works. If it does then you know the problem is with the charger or AVR2 device and wiring. If it behaves the same you know the problem is with the EVSE or building wiring to the EVSE.

Conversely, you can take your charger setup to a working EVSE and plug into it. If the charger wakes up then you know you have that side of it wired correctly.

Best Wishes!


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